[Narrator] A self-made couple making plans
for the next stage of their lives.
They were getting ready to have a quiet retirement.
They were such a beautiful couple.
They would give you their shirt off their back.
They had a lotta friends
and loved spending time with family.
[Narrator] Gunned down execution-style in their own home.
It just seemed to make no sense.
Who would do that and what could possibly be the motive?
[Narrator] While searching for the killer,
investigators uncover a world of greed and deceit.
We looked at desperation.
She was desperate for money.
He felt he had been treated badly,
basically kicked to the curb.
People were saying that he was very upset.
It certainly is motive.
[Narrator] A series of chilling discoveries...
We learned that he was receiving
hundreds of thousands of dollars.
Everything he's told us is a lie.
[Narrator] ...points to a killer no one ever imagined.
People were shocked.
It shows what a messed-up psyche he's got.
It was unbelievable how somebody can be that cold-blooded.
[Narrator] On the outskirts of La Crosse, Wisconsin
lies the prestigious neighborhood
of Barre Mills.
In early spring of 2010,
this quiet community is rocked
by a disturbing 911 call.
[Narrator] Police race to the scene.
First-responding officers lead 40-year-old Eric Koula away
from his deceased parents' home
while detectives head inside.
We could see that there was
a male lying on the kitchen floor.
There was a large pool of blood around his head.
The blood was
coagulated so it had been there a while.
You know, it wasn't fresh blood.
He was holding his car keys in one hand.
He had his coat on,
so it was clear that he had just walked in the door.
He hadn't even set everything on the counter yet.
As I viewed the male victim,
the wound appeared to be a gunshot.
It was near the temple of his head.
Around the corner is like a hallway entryway
with a computer desk,
and the female victim was there.
She was shot in the head also.
Her hands were on the keyboard,
and so you could see that she had been typing
before she was shot.
What she was typing didn't appear to be significant,
but it made us believe that she had no idea
that someone was behind her going to shoot her.
It appeared that they ambushed them.
[Narrator] The victims are identified
as 68-year-old Dennis Koula and his wife,
65-year-old Merna.
As investigators examine the scene,
they make note of other telling details.
We didn't know if it was a single killer
or more than one person,
but you would expect more disturbance
if there were more than one
or that they would have overpowered the victims,
and that didn't seem to have happened.
With Merna sitting at the computer comfortably,
that led us to wonder if she was the first to be killed,
and her husband, Dennis, came home,
and he was the second one shot.
There was the smell of decomposition.
At that point,
we weren't sure how many days earlier they were killed.
But we needed to get the information pretty quickly.
[Narrator] Detectives find no sign of forced entry
and no indication of any kind of struggle.
The crime lab comes in.
They collect fingerprints and DNA
and the computer for analysis.
We went upstairs and we noticed in the one bedroom,
there was a dresser that was disturbed,
and it appeared that it had been ransacked.
What was unusual about it was the person started at the top
and worked their way down the chest of drawers,
but if you did it that way,
you wouldn't be able to see what was in the drawer below it.
This looked like someone was trying
to make it look like a burglary,
but nothing seemed to be missing.
And there were many other valuables in the house,
including Merna's purse,
and Dennis' wallet was still in his back pocket.
It looked like this was staged, quite frankly.
[Narrator] While investigators continue searching
for clues, they find what could be a key piece of evidence.
The bedroom had a .22 rifle in the closet,
and there was also a box of .22 shells on a shelf
that had been moved and partially opened.
That was very possibly the gun
that was used in the homicides.
So the gun is sent to the crime lab for an analysis.
[Narrator] As the crime scene investigation continues,
news of the murders spreads quickly
through the close-knit community.
When I heard about it,
I thought, "I can't believe this is happening."
I was devastated.
It hit me real hard.
It was like, why would somebody kill them?
Everybody loved 'em.
[Narrator] Born and raised in Wisconsin,
Dennis and Merna Koula had been happily married
for 42 years.
Dennis and Merna had a lotta friends.
They had deep roots here.
They had children and grandchildren,
and they were very popular.
I didn't hear of anyone that had anything bad to say
about either one of 'em.
[Narrator] From humble beginnings,
Dennis rose to become a successful businessman.
Dennis had graduated as a pharmacist,
and he had owned a number of pharmacies and businesses
throughout the years in different locations.
I worked with him for two years.
As a boss, he was down-to-Earth,
fantastic guy.
If you needed something, he was there.
He treated me like a daughter.
[Narrator] Dennis was successful in life and in love.
Him and his wife,
they were always happy having a good time.
Merna had a lot of energy.
She was very sociable.
Merna was very well educated,
and she was presently teaching part-time
on a substitute basis.
They had a good marriage.
They enjoyed life.
[Narrator] The couple had two children:
their son, Eric, and 37-year-old daughter Cindy.
Both were married with families of their own.
Their family seemed pretty tight.
Dennis and Merna,
they were involved with their kids
and involved with their grandkids.
These were parents who were very dedicated.
They really wanted the best for their kids
and loved spending time with family.
Dennis and Merna were getting ready
to have a quiet retirement and relaxing and enjoying life.
[Narrator] Now, those dreams
had been brutally snatched away.
Both shot?
I would've never, never in my life,
expected something like this to happen.
It just seemed to make no sense.
We're trying to understand who would do that
and what would be the motive.
[Narrator] While police bring the Koulas' son, Eric,
into the station to get more information,
investigators go door to door looking for witnesses.
We'd start canvassing to see if anyone saw anything,
heard anything.
Nobody in the neighborhood had seen anything suspicious.
For them, it was just mostly shock.
They couldn't believe that these two people had been killed.
[Narrator] As detectives continue to search for a lead,
they get their first break.
One of the neighbors mentioned
that he thought he knew the motive
and why it happened and also the murderer.
He was very concerned.
He believed that his life was in danger.
He felt that he may be next.
This neighbor, Steve Burgess, was a banker,
and he thought that he may have been the intended target
of the homicide.
His reasoning was he had got a threatening call
multiple times from a person that threatened to kill him.
[Narrator] Coming up, new evidence emerges.
The day after the homicides,
he cashed this $50,000 check and never told us.
[Narrator] And family secrets come to light.
There was some jealousy, maybe bad blood between the two.
Dennis always complained that he was worthless
and that he didn't want to work.
She had apparently lit into Dennis in a rage.
[Narrator] Until a disturbing clue
reveals a twisted plan...
Someone had put this threatening note in his mailbox.
Now he believes that someone was out to get him.
[Narrator] ...and exposes a cold-blooded betrayal
nobody saw coming.
I never thought they were the kind of person
that would do something like that.
It was extremely unexpected.
It's just chilling.
[Narrator] Grandparents Merna and Dennis Koula
have been brutally executed in their own home.
Now, one of their neighbors, banker Steve Burgess,
tells investigators the killer could be coming after him.
He was very concerned,
and he believed that someone was out to get him,
and he didn't know who, but,
the homicides may have been intended
for him and his family.
[Narrator] Detectives ask Steve
why someone would want him dead.
So, at that time, the market crash,
there was people with money issues.
A lotta people came to him at the bank for loans,
but they had no collateral,
so people were very angry
that Steve would not give them loans.
The last threat was a couple of days earlier.
It was a threat of violence.
It certainly had to be taken serious.
[Narrator] If Steve was the intended target,
how did Dennis and Merna end up gunned down instead?
What he explained was a Google Earth search
on the Burgess' house showed the wrong address,
showed Dennis and Merna's address instead of his,
and he thought that the killer killed the wrong people.
He felt that somebody had come to his house
to follow through on the threat,
but they ended up at Dennis and Merna's residence.
It was a concern that this possibly could've been a mistake
on behalf of the murderer,
and the homicides were not intended for Dennis and Merna.
[Narrator] Before investigators can pursue the lead,
the autopsy results arrive.
The autopsy report determined that they were both shot
with a .22 caliber rifle.
But it was inconclusive.
There wasn't enough bullet fragment left
to tell if it came from the gun that we found in the house.
No fingerprints were found,
I mean, even from the victims,
like the gun had been cleaned up.
The autopsy report also confirmed
that they had been deceased for a few days
before the 911 call.
It was likely that they were killed on that Friday.
[Narrator] The time of death sheds new light
on the threatening phone call
made to neighbor Steve Burgess.
We saw that call had come in Sunday morning
after the Koulas were murdered,
so the timeline just, it didn't make any sense.
We were able to determine
that the threats against Steve Burgess
had nothing to do with the deaths of Dennis and Merna.
[Narrator] With their first lead a bust,
detectives turn their attention closer to home.
We knew Eric and his sister, Cindy,
were very close to their parents.
Eric did day trading and stuff like that, work on stocks.
He was doing well.
Dennis and Eric were pretty close.
Some people would say like bread and butter.
They'd have get-togethers all the time.
Eric was the one that found the bodies.
We needed the conversation with Eric
for information that he might be able to provide us.
[Narrator] Hoping he can provide details about the crime,
investigators interview Eric at the station.
Eric was still extremely emotional
over the death of his parents,
but he said he wanted to be as helpful as he possibly could
and would do whatever he could
to try to find who was responsible.
[Narrator] Detectives ask how he came to find
his parents had been killed.
He said the school called
and said that Merna hadn't shown up for work.
They'd called his parents and they didn't respond.
So Eric tried calling and was unable to get an answer,
so he called his sister
and asked if she had any contact with them,
and she had not.
He became concerned and drove over to the house.
Once he walked in the house,
he observed his father lying on the kitchen floor
and started searching for his mom
and then also found her deceased.
Eric said he was extremely close to his parents.
His dad, you know, supported all of his endeavors.
They were just the best of buddies.
We asked Eric what was the last time
he had seen his parents,
and he said a few days before the homicides.
He'd visited them like he did all the time.
He said his dad was working on the deck,
and his mom was doing laundry.
There didn't seem to be anything unusual.
[Narrator] Investigators ask Eric where he was
on the day of the murders.
He said that Friday was he and his wife's anniversary.
He had worked 'til 2:00,
then he helped his buddy, Mike, do some work in a bathroom.
They were renovating a bathroom.
Eric had told us that he had gone to two stores
after leaving his buddy's house,
looking for a specific plant that his wife liked,
a hanging plant.
[Narrator] Eric presents a receipt stamped at 6:15 PM.
After he bought the plant, he went directly home,
and they got ready to go out for the evening with friends
to celebrate the anniversary.
Eric said that he had tried over the weekend
to contact his parents and wasn't able to do so.
He was becoming concerned
but just thought that they were busy.
[Narrator] When asked who might've
wanted to harm his parents,
Eric says they were well-liked and had no enemies.
It seemed really strange, really unusual.
No reason for the victims to be killed, both victims killed.
[Narrator] Before concluding Eric's interview,
detectives get results back from the crime lab.
The report came back indicating that the time of death,
based on the computer analysis,
was 5:41 on that Friday.
Merna was using the computer,
and the last keystroke was 5:41 PM,
so that gave us a timestamp.
That's huge.
[Narrator] With the keystroke data,
detectives verify Eric's alibi.
We spoke to his friend, Mike, and Mike said,
"Yes, Eric was here until about 5:30 when he left,
and he was gonna go to the store."
So he basically confirmed
what Eric was telling us was correct.
The receipt combined with what his friend, Mike, said,
it appeared that there wasn't enough time
for Eric to commit the crime.
Also, it just seemed very unlikely
that someone who loved his mother and father very much
could be involved in something like this.
[Narrator] Before Eric leaves the police station,
he remembers crucial information
that takes detectives by surprise.
Eric had told us that his sister, Cindy,
and her husband, Pat,
were being financially supported by Dennis and Merna
and their dad, Dennis,
told Cindy they were getting cut off financially.
The Friday morning of the homicides,
Cindy had called Dennis.
Dennis let her know
that there was not gonna be any more money.
She became very upset.
[Narrator] Had there been an argument over money,
leading Cindy to kill?
That's extremely unexpected,
but she did have motive,
so we start looking at Cindy as a suspect.
[Narrator] Police investigating the double homicide
of Dennis and Merna Koula believe their daughter, Cindy,
may have been angry with her father
after he cut off financial support.
The two had a tense conversation
just hours before the murders.
When we started talking
to the circle of friends and family,
we were told Dennis was more than generous.
He gave tens of thousands to Cindy and her husband.
Cindy relied on her parents.
They needed this money to pay their bills.
When Dennis had told Cindy that he was cutting her off,
she didn't know how those bills were gonna get paid.
[Narrator] Detectives learn the Koulas' children
are set to inherit over $700,000 from their parents' death.
While son Eric is known in the community
as a successful businessman,
Cindy's circumstances are different.
Cindy didn't have much money, if any,
and she was constantly asking for money
because they were not making ends meet.
She was working a minimum-wage job or a little above that,
and Pat, her husband, couldn't keep a job.
Would quit or get fired.
They were living paycheck-to-paycheck
and Dennis's handout-to-handout.
Me and Dennis would talk about Cindy at the pharmacy,
and he kept telling me that he was sick and tired
of supporting her every month,
helping 'em out with their bills and stuff like that.
That Friday morning, he was very upset and he said,
"My daughter called me this morning crying on the phone
because I told my daughter
that I'm cutting her and her husband off."
When she would get upset,
she would get just extreme over-the-top emotions.
Cindy hearing that the cash cow was being butchered
would be a reason for her to now go off the rails,
and that went from bad to worse.
Cindy became a strong suspect.
[Narrator] Police bring Cindy into the station
for questioning.
Cindy appeared broke-up over the deaths of her parents,
but she really laid out the family dynamic.
Her parents had considered her the black sheep
of the family.
She said that she didn't believe her parents cared about her
like they cared about Eric,
and she was upset with how they treated her.
She told us, according to her parents,
that Eric could do no wrong
and that Cindy was a disappointment
and continued to be a disappointment.
But Cindy denied that she had anything to do
with her parents' death,
even though there was this friction between them.
[Narrator] Investigators question Cindy
about the argument with her father
the morning of the murders.
Cindy downplayed the conversation she had with her father.
She said just that she was disappointed
her father had said he wouldn't give her any money,
but it wasn't a negative conversation.
[Narrator] Detectives wonder if Cindy is more guilty
than she's letting on.
There was a lot of tension between Cindy and her parents.
There was disapproval there.
We looked at desperation.
She was desperate for money.
With the inheritance and given her bad feelings,
all these things could lead to the fact
that she may have been the one
that took the lives of her parents.
[Narrator] With suspicion swirling,
police ask Cindy where she was when her parents were killed.
On Friday, she was working
and had left at 4:45.
They have a time clock.
She had punched out.
After work, she had stopped at the store just after 5:30.
She'd purchased beer and ice,
and then her and Patrick had a barbecue with the neighbors.
[Narrator] Police work to confirm Cindy's alibi.
She was working.
That was verified then.
Cindy had stopped at a Kwik Trip,
and the Kwik Trips all have video,
so she was on camera at a Kwik Trip near her home
at the time of the homicides,
not anywhere near her parents.
[Narrator] While Cindy is ruled out as the shooter,
her husband, Patrick, comes into focus.
Family and friends said that Patrick did not get along
with Dennis and Merna,
and Patrick stood to inherit a substantial amount of money
along with Cindy.
Dennis did not like her husband at all.
He told me that Cindy's husband married Cindy for the money
'cause he knew that Dennis and Merna had money.
Dennis always complained that his son-in-law, Patrick,
was worthless
and that he didn't wanna work.
He sits and plays with the video games,
and he's too lazy to go find a job.
[Narrator] Investigators dig deeper
into Patrick's relationship with his in-laws.
Talking to family and friends,
we learned that Dennis and Merna were upset
when Patrick and Cindy got married.
They asked Cindy not to marry him.
They felt that he lacked motivation,
and they remained unhappy with him.
I think the feeling was mutual.
According to some reports,
when there was alcohol involved,
he had been a violent person.
Apparently the Friday morning of the homicides,
Cindy told Patrick that they were not gonna be getting
any more money.
People were saying that Patrick
was even more angry than Cindy
that they were being cut off financially.
It was a large red flag.
[Narrator] Detectives also
learn Patrick had the capability
to pull off an execution-style hit.
Eric and other relatives were now pointing us
toward Patrick,
saying that he was a Marine
and that he knew how to handle weapons.
It certainly moves Patrick up to the top of the list,
as far as suspects.
[Narrator] Police hunting
the killer of Dennis and Merna Koula
believe their son-in-law, Patrick Cowell,
has motive for murder.
Patrick was a great interest to us
because he did not get along with Dennis and Merna,
and he stood to inherit a lot of money,
so it certainly is motive,
and Patrick was in the Marine Corps,
so he would be an expert marksman.
When I heard that the police are starting to question him,
I thought maybe after Dennis mentioned cutting them off,
that might've triggered his son-in-law to kill them both.
[Narrator] At the police station,
detectives confront Patrick about his relationship
with his in-laws.
Patrick said that he was not popular in that family,
that he was not comfortable with them,
they weren't comfortable with him.
It was kind of a cold relationship.
He knew from Cindy that they were being cut off
from Dennis and Merna.
He wasn't happy about it,
but he denied having any involvement in the homicides.
[Narrator] Investigators press Patrick about where he was
at the time of the murders.
He was without a job at the time,
and basically he spent most of his day on the sofa
with a XBOX.
We asked if he had any guns in the house,
and he agreed that he did.
We asked if he would turn those over to us,
and he said he would.
[Narrator] As detectives wrap up
their interview with Patrick,
patrol officers are dispatched
to collect the gun and gaming console,
which are then sent on to the crime lab.
The gun had been analyzed
and, in fact, was eliminated as the weapon used
to kill Dennis and Merna.
Also, we were able to prove through the crime lab
that he was on the XBOX at the time he said he was,
and so that eliminated him
because he was home at the time
that Dennis and Merna were killed.
[Narrator] With Patrick ruled out,
police are left scrambling for new suspects.
The unsolved homicides leave the community on edge.
When a crime like this happens in a small town,
like Barre Mills,
there's a lot of pressure
on law enforcement to get it solved.
People want answers.
These aren't strangers to them.
These are people they know.
People in that neighborhood were fearful.
You know, the closer you are to something like that,
the more concerned you are.
We were kinda scared for our lives
'cause we didn't know why something like this would happen.
[Narrator] Looking for new leads,
investigators dig into Dennis's business connections
and the wealthy pharmacist's other ventures around town.
Dennis had a nephew, Nick Harring,
who was promised a business from Dennis.
They were gonna open a car dealership together
and actually did.
What we understood was that Nick was very familiar
with running car dealerships and had done a good job.
[Narrator] Business was good
but then Dennis changed the deal.
As the dealership was up and running,
Dennis brought Eric, his son,
in to start running it with Nick,
and there was some jealousy,
maybe bad blood between the two.
Nick was complaining all the time,
so Dennis had to go help out with the business.
Dennis said they could not get along together,
and he ended up buying Nick out.
At that point, Nick was quite unhappy,
and there was some falling out.
[Narrator] Tension mounted until Dennis sold the business,
leaving Nick resentful.
Nick lost a pretty substantial amount of money,
so he would certainly have reason to be upset.
[Narrator] Could Nick have harbored
a deadly desire for revenge?
Police bring him into the station for questioning.
We spoke to Nick Harring,
and he admitted that the relationship had soured.
Nick had said that Dennis had given him
too low amount for the business
and that he got cheated outta some profit.
Nick felt that he had been treated badly,
basically kicked to the curb by his uncle.
[Narrator] Despite the bad blood,
Nick insists he's not involved in the murders.
Nick said that it was in the past,
that he had started his own car dealership.
He was successful and that, although it was upsetting,
he wouldn't hold a grudge,
and he had no reason to kill Dennis and Merna.
Nick said that he had worked until about 5:30.
Then he had picked up his girlfriend,
and they'd gone out to the tavern.
We were able to confirm that he was at work all day,
and then the bartender where they were at could confirm
that he and his girlfriend had spent the evening there,
and so we were able to eliminate him.
[Narrator] Having ruled out yet another suspect,
the investigation into the Koula murders hits a road block.
It was very disturbing
because it just seemed to make no sense.
Here's a couple that are retirement age,
had long, successful careers.
For someone to come in and just murder them,
It's senseless,
but we were still trying to understand who would do that
and what would be the motive.
[Narrator] One week after the murders,
police receive news that jolts the investigation
back to life.
We get a call that a patrol car's being sent out
to Eric Koula's residence
for a suspicious item in the mailbox.
Eric said that he had got a threatening letter.
He was now extremely concerned
that he was going to get killed.
[Narrator] One week after Dennis and Merna Koula
are ruthlessly gunned down in their own home,
police learn their 40-year-old son, Eric,
has received a threatening note.
Could he be the next target?
Someone had put this note in his mailbox.
He was really, really concerned.
This note said, "Fixed you."
The message is kind of unusual,
but Eric thought they'd killed his parents
and were now gonna come after him.
He had no idea who would've left it or where it came from.
There was an envelope but it wasn't mailed.
The handwriting looked like it was done
by someone very young.
It was so strange.
It was probably written that way
so a handwriting analysis couldn't be done.
[Narrator] When it comes to Eric's safety,
detectives don't take any chances.
We have to try to figure out what was going on.
We had an investigator and a camera to watch his property
while we start canvassing Eric's neighborhood
to see if anyone saw anything.
[Narrator] But, with no witnesses,
police are still left with no idea who placed the note.
This is perplexing.
We're trying to determine was this somebody local
or was this someone from outta the area?
We were very concerned.
[Narrator] With this new potential threat,
investigators cast a wider net to find the Koulas' killer,
but when they scour Dennis and Merna's computers,
phones, and finances,
they're surprised at what they find.
We subpoenaed Dennis and Merna's bank records
and noticed that there's a check written and cashed
on Dennis and Merna's account for $50,000.
It's cashed on the day after the murder,
and it's made out to Eric Koula
and was deposited into Eric's bank account.
It seemed really strange,
so you just found your parents dead,
and the next day you go cash a check for $50K?
It had to be looked at.
[Narrator] Detectives reach out to Eric,
hoping to learn more details.
Eric's explanation is his dad gave it to him
on the day that he had stopped over at his parents' house.
That's very interesting
because all the conversations we had with Eric,
he never mentioned this,
and suddenly we have a check for $50,000,
and if everything was okay,
why wouldn't he tell us about it?
To have a check that was deposited
the day after the murders by a family member,
that set off alarms for investigators.
After we find that check,
we look for other checks.
We used a forensic accountant
to review Eric's finances
because it was quite complicated with the day trading
that he was involved in.
When the accountant went through it with us
and explained what we were looking at,
I think we almost fell off our chairs
because we had no idea that this was what was going on.
He told everybody that he was extremely successful
with his day trading,
but Eric was broke.
He was day trading but it was a myth,
as far as making profit.
The person looking at his financials basically called BS.
She told us, "This guy's worth nothing.
He's worth about $2,000 total."
He was blowing smoke.
[Narrator] Then, police uncover more startling information
about Eric's financial circumstances.
We learn that Eric was also going to his parents
and receiving large amounts of money.
Through the years, it was hundreds of thousands of dollars.
He led everybody to believe that he was doing so well,
including his wife.
Eric told her that he was making a lotta money.
There was nothing to worry about,
that he was just doing great.
Despite everyone's impression
that Eric was this successful day trader,
his parents had been funding his and his family's lifestyle.
If he was gonna have to admit that to family and friends,
it was going to be devastating.
[Narrator] Detectives learn when Dennis and Merna
stopped financially supporting their daughter, Cindy,
they also cut off Eric.
We knew just shortly before Dennis and Merna were killed,
Eric found out that he was no longer getting money
from his parents.
[Narrator] The damning evidence continues to pile up
against Eric.
Dennis told me he was giving money to Eric,
but basically he was done giving to both kids.
He says, "I need to tell them I'm done supporting them.
It's about time I put my foot down and cut them off."
[Narrator] As investigators start to discover
that Eric is not what he seems,
shocking results come back from the lab.
The state crime lab did a handwriting analysis
on that check for $50,000.
It wasn't Dennis's signature on that check.
We found out that it was Eric's handwriting
and that he had forged his father's name on that check.
Everything he's told us is a lie,
so things are starting to really roll toward Eric.
[Narrator] Police obtain a warrant to search Eric's home,
hoping to find additional incriminating evidence.
We're in the basement.
Among other things
was a box of envelopes in a desk drawer.
The "fixed you" note had a security envelope,
and every one of 'em has a different pattern
for their security pattern.
Lo and behold, those envelopes have the same pattern.
We were able to determine that envelope in Eric's mailbox
with the "fixed you" note came
from the box of envelopes in his home.
From his fire pit in his backyard,
we found things that would be associated
with making a "fixed you" note.
A spring from a spiral notebook,
the letter was written on spiral notebook paper.
A barrel of a pen used to write the address,
those types of things are in the fire,
so that "fixed you" note came from his house.
It didn't look good for Eric.
[Narrator] In the search,
detectives also discover a .22 caliber rifle,
similar to what police believe was the murder weapon.
The gun is sent to the ballistics lab for testing.
With the lies and forgery,
we were pretty confident that Eric was our guy.
But, at that point, Eric had an alibi for the entire time
that the homicides were occurring,
so we're trying to figure out how he shot Dennis and Merna.
[Narrator] Detectives investigating the double homicide
of Dennis and Merna Koula suspect the couple's own son,
40-year-old Eric is the killer,
but they need hard evidence to lay charges.
We went out and started re-interviewing witnesses
and reviewing all the evidence that we had.
[Narrator] As detectives try to learn more details
about Eric's connection to the crime,
the ballistics results come back.
Police wonder if the rifle found in Eric's home
will prove to be the murder weapon.
Dennis and Merna were shot with a .22 caliber rifle,
but Eric's gun wasn't the gun
that was involved in the crime.
[Narrator] Undeterred, detectives re-check Eric's alibi
for when his parents were being murdered.
The time of death based on
the computer analysis was 5:41
on that Friday.
Prior to the homicide,
Eric said that he'd helped his buddy, Mike,
renovating a bathroom.
When we originally talked to Mike,
he said that Eric had left his house about 5:30,
but when we re-interviewed him,
he said it's very possible it could've been earlier.
Once Mike's story changed,
we really thought that we were heading
in the right direction.
[Narrator] Investigators take a closer look
at Eric's timeline.
Eric had told us that he had gone to two stores
after leaving his buddy's house
to get a specific plant for his wife.
At the time of the homicide,
he had stopped at the first store,
and that store didn't have it,
so he had to go to the other store,
got the plant and produced a receipt.
[Narrator] Eric's receipt is stamped 6:15 PM.
The second store is located only 10 minutes
from the Koulas' residence,
but where was Eric at 5:41 when his parents were being shot?
We checked with the garden center
at the first one he went to,
and they had plenty of those plants on the day and time
that Eric said that they didn't have any.
We also reviewed video footage,
and he's not there,
nor is his vehicle seen coming or leaving the parking lot,
so there was a window of opportunity
for Eric to commit the murders.
He had no alibi for the time
that the computer showed that Merna was shot.
[Narrator] With Eric's alibi torn apart,
detectives bring him in for another interview.
They begin by confronting Eric
about forging the $50,000 check.
Eric explained that he had permission from his dad
to write checks out to himself
and that his dad had actually given him the check
but just was too busy,
so told him to sign it himself.
He told us, "I write 'em all the time,"
and that that was commonplace for him to do that.
It's a lie and a provable one.
He's never written one.
He couldn't produce a single check that he had ever written.
He was confronted with the "fixed you" note
and about the envelopes
and that they did come from his house.
With what we found and what we knew about his financials,
all of those things together are great evidence.
We just went down item after item after item after item,
and Eric acted, in my opinion, desperate,
and he wanted to leave.
[Narrator] But Eric was no longer free to go.
On July 29th, 2010, police charge Eric
with the murder of his parents, Dennis and Merna Koula.
What we believe started this whole crime in motion
was the fact that Eric was being cut off financially.
He was desperate.
[Narrator] Detectives piece together
how the double homicide unfolded.
We believe he went to see his mom at their home,
and Merna was sitting at the computer,
and then Eric walked upstairs,
got the gun that was located in the closet,
came down and shot his mother,
and then waited for his father to arrive.
When Dennis came home,
he was shot almost immediately
within seconds after he walked through that door.
[Narrator] After the murders, Eric wipes the gun clean
and returns it to the closet.
Eric then took a check and said to himself,
"$50,000'll get me through until the will is settled."
After he shot his parents,
he went to a garden center,
bought the plant for his alibi,
and went home to celebrate
their anniversary dinner that night.
He's as cold-blooded as a murder-for-hire man.
His parents did nothing but love him
and take care of him his whole life.
He's a narcissistic little son of a bitch
and thought that his dad owed him a living.
[Narrator] Eric Koula's arrest stuns the community.
Everyone thought that he was this golden child,
that he had a great relationship with his parents,
that he was this successful day trader.
That he could have done this?
People were shocked.
I would've never expected Eric to do this.
The way Dennis talked about him,
always bragged about his son,
and never thought he was the kind of person
that would do something like that.
[Narrator] In June 2012,
two years after Dennis and Merna Koula were killed,
a jury finds their son, Eric, guilty of intentional murder.
His sister, Cindy, during the sentencing hearing,
was sobbing and she begged the judge in that courtroom
to make sure justice was done that day.
[Narrator] Eric Koula is sentenced
to two consecutive life terms,
plus six years for forgery.
Many times, I've thought about how somebody could do that,
and I just simply can't fathom it.
I guess we all lose a bit of our innocence
when this kind of thing happens.
[Narrator] Merna and Dennis are still dearly missed
by their family and friends.
They were such a beautiful couple.
They would give you their shirt off their back.
I think of 'em very often,
and my memory of Dennis is always a smiley face.
I do miss him a lot.
Sometimes I still think,
"Boy, why did it have to be you?"
He'd still be living right now,
happy life, probably retired,
enjoying his grandkids,
and Merna would probably still be dragging him on vacation.