The Girl From Wahoo | Post Mortem | Forensic Files

Welcome to Postmortem. I'm your host, Ann [music] Marie Green, and today we're discussing the murder of Mary K. Hessie,
a 17-year-old high school student from Wahoo, Nebraska. She was killed in 1969. 55 years and multiple investigations
later, one of the very first suspects, Joseph Ambrose, was finally arrested and charged with Mary Kay's murder. Joining
me now is 48 Hours correspondent Natalie Morales. Natalie, you worked on this uh
episode. It was I mean, it was a doozy. >> Yes. Uh it was. And good to see you again, Anarie. In fact, this is one of
the longest cold cases that 48 Hours has been working on. Before we dive deeper,
just a reminder to everyone, if you haven't listened to this episode of 48 Hours, you're going to find it uh in the
podcast feed just below this one. Listen and then come on back for this conversation. So, Natalie, you know,
watching the years tick by, I really didn't think that there was going to be a resolution uh to this murder at all.
And I wonder what it was that kept detectives coming back to the case over and over again when with each year it
seemed like it would have been more and more of a long shot to get a resolution.
>> Yeah. You know, this was a real shock to the town of Wahoo. I mean, it really
lost its innocence after the murder of Mary Kay Hessie back in 1969. Murders there in this town were very rare. But
afterwards, people were afraid to go to Wahoo because that's where the girl was murdered. It kind of developed that
negative reputation and connotation, you know. And if you think back, I mean, this was these were the days 1969, it
was the Satie Hawkins dance. Girls would bring and Mary Kay Hessie, in fact, was
bringing her little straw pocket book to school. I remember, in fact, having a bag very much like that. And even the
the lucky rabbit uh keychain was something that I even had as a kid growing up. >> It was like a time capsule. Um reminding
us of kind of a much more innocent time. And when you go back to Wahoo, you know,
it really does look a lot. We compared, you know, the footage throughout the hour from 1969 to then we were a little
bit of a time lapse to 1999 and here here we are 2026 covering this case again. And really not much has changed.
A lot of the things there still remain the same. And another interesting people may think, well, Wahoo, why does that
sound so familiar? Well, David Letterman used to have a shtick on his show where
he would check in with our home office in Wahoo and we drove past the what was the old phone booth, the old glass phone
booth that you would see back in the day. And people would put post-it notes on that phone booth. And that was the
so-called office in Wahoo that David Letterman was referring to. And just to bring people back to the case, this is
how things unfold that day. March 25th, 1969. Mary Kay's parents reported her missing
that evening when she failed to come home from school. A witness reported seeing Mary Kay getting into a car with
two men. Her body is then found in a ditch along a rural road. Uh she has been beaten and she has been stabbed to
death. >> Yeah, >> we know that when it comes to homicides, you know, those first few hours, those
first few days, they are crucial when it comes to solving a case like this. Why was it so difficult to sort of nail down
suspects for this murder in those early days, especially when there was an eyewitness who saw her getting into a
vehicle? >> Yes. And the police at the time did question all those witnesses. Investigators, you know, went about
doing the job as best they could back then with the tools that they had. Investigators now looking back on the
case and the prosecutors, you know, they reminded us 1969, I mean, this type of murder case, a homicide in Wahoo,
Nebraska, that was unheard of. In fact, the Nebraska State Patrol had just started to broaden the scope of things
that they got involved with, like criminal investigations. Also, it was it was spread out over various different
law enforcement departments. You know, the police department covered some of it. The sheriff's office had part of the
case. The state patrol got involved. And some of the evidence of this case was even sent to the FBI, which was at that
time under Jay Edgar Hoover. All was sent to J. Edgar Hoover's attention. And the current prosecutors say that the
evidence was scattered all over the place across these different agencies. So that made sort of pinning down things
a little more difficult. >> So then what sort of evidence did they have, you know, at that time?
>> Well, really it came down to analyzing and and taking stock of that crime scene. you know, they saw footprints in
along the road that showed that it appeared that Mary Kay Hessie um got out of the vehicle and it seemed like she
was running and they could tell this according to the investigators back then because the strides were long strides um
and they also saw another shoe print by her footprints. Her her school books were found along the side of the road as
well as that pocketbook that I mentioned stacked neatly on the road. So investigators believe that the killer
might have placed them on the side of the road realizing, you know, I've got to get rid of this evidence, but this
was long before the days of DNA testing. So all of that would be preserved somewhat, but yet it would take years
for them to go back and analyze and look at the case again using new tools with science advancing and catching up to
where we are today. I thought it was really interesting that they relied a lot on the polygraph tests and now we
know polygraph tests are, you know, I don't know how often they're used because we know that people can beat
them. But Joseph Ambrose, they speak to him at the time. He's 22 years old. He's
questioned because he was seen talking to Mary Kay weeks before the murder. He tells investigators that he was actually
hanging out with a friend, Wayne Greaser. They were at a number of different locations the night of the
murder. Both of the men though take and they pass polygraph tests. Um nowadays polygraphs are usually not admissible in
court. >> Yeah. And you know today I mean I think scientific research suggests that
polygraph tests they're generally not reliable as you said people can beat those tests. Also if you're nervous and
you're taking a polygraph test I don't know if you've ever been hooked up to one of those but you know you get
nervous when you're taking that. I I had it done once, you know, just as a tool and your levels are spiking just because
you're nervous and it could change the the polygraph result. Um so Ambrose did pass that original polygraph, but we
again don't really know what exactly he was asked and um they didn't even look at, you know, Ambrose's car at the time.
And it's believed, you know, if all of this happened, it happened within the car and outside of the car, that would
have been the crime scene. And also, they never really compared the shoe print that they found frozen to
Ambrose's. Although Ambrose was a size 9 and a half, which turns out was the size
of that print. But it would only be years later now as recent investigators started putting the pieces together that
they would make that connection. And then in 1999, we have Sergeant Bob Frank. He picks up the case again. And
48 Hours cameras were actually there following the investigation. That's right. You know, we filmed Sergeant
Frank. This was back when they formed this this newly formed cold case team to tackle this case. And they worked on it
for a year because this was a 30-year cold case at the time. So we at 48 Hours back then in 1999 were interested to see
if the cold case team using DNA technology if they could find any new DNA evidence with the new tools and the
science. So we filmed the team for quite a while and and it was evident though at
the time that the case didn't seem to be moving forward anywhere. It remained cold. So the story was really put on the
shelf. That footage also put on the shelf for us at 48 hours. But like we say, we always like to follow cases for
as long as we can until there's some sort of resolution. And we became aware that an arrest had been made in 2024.
And we found all the footage that we had and realized, boy, you know, we do have
a lot here. And and this would make for a fascinating update. Hm. And in watching the archival footage, I was
sort of struck by how much access 48 hours had. I don't think we would have the same level of access today. I mean,
it really was like being a fly on the wall in the investigation as it was carrying on. We we went into the
interrogation room with them. They made it seem like there was this so-called cold case task force. They waxed up the
tables, even waxed the chairs so that anybody that they brought in for questioning would be uncomfortable and
like it would be slick and sliding around. You see a bunch of names up on the whiteboard in the interview room.
That was again one of the tactics they used just to try to make it seem like, oh, they're making a break in the case.
Look at these names. Although a lot of the names were fake names. One of the investigators even put his own name on
the whiteboard. So that kind of insight into a case, I don't think we've we've seen something like that today. Um it
shows though the lengths that the detectives went through to try to get some sort of break in the case and new
information. Yeah. And you get some real insight into sort of how they're thinking about this investigation.
Sergeant Frank scour these old case reports and what he notices is that Joseph Ambrose and Wayne Greaser. They
keep coming up over and over again in witness statements. So then he interviews people who knew the men at
the time of the murder. And then eventually he actually travels to Florida to speak with Joseph Ambrose
himself. And we have some of that sound. >> We have a wonderful thing called DNA,
right? >> And we're going to be able to show who she struggled with. Okay. Um, again, you know, we have all this little
bits of information here and there that fit together that you were there. Not necessarily that you did it, but that
you were there when it happened. >> That's yet to be proven. I mean, I wasn't there. Like I said, I had nothing
to do with it. Uh, and you're you're free to take blood, anything you want. >> You know, we even had incredible access.
the the crew that was there following Sergeant Frank at the time. They were parked right outside when when they
picked up Ambrose up for questioning. Ambrose has always been insistent since shortly after the murder that he had
nothing to do with this. Um he though, as you heard, seemed to be cooperative. He even offered up his blood, but he
knew investigators also had a search warrant for his house. So, one of the few times we do see Ambrose get just a
little bit agitated is when Frank brings up, you know, the man who told authorities that Greaser confessed that
he and Ambrose had driven Mary Kay to that field area and that it was Ambrose who killed her. However, detectives at
the time couldn't talk to Wayne Greaser anymore because he had died by suicide in 1977.
Given all of that, there was no match when it came to the DNA to Mary Kay's books or her clothes. So ultimately, it
came down to this case once again stalling because, you know, the county attorney at the time felt there just
wasn't enough to move forward in the case. They also they were working off of a grant. They started to run out [music]
of money. So in 2000, Sergeant Bob Frank unfortunately had to stop working on the
case. Welcome back. So, the case is cold and then fast forward to 2015. Enter [music]
Ted Green. He is an investigator for the Saunders County Attorney's Office and he
starts looking into the Mary Kay. Hessie murder. This is a small town, I presume,
with limited resources. yet, you know, they still sort of managed to scr up the money to keep this investigation open.
How were they able to do that? >> Yeah. You know, I it was up to the prosecutor and like I said, this is a
case that really hung over the community. So, it was something that always remained on people's minds. Time
though, as as you know, was not on their side. Witnesses of course were dying, memories are fading, and Ambrose was
getting old. So prosecutors told us they felt it was now or never. And you know,
Green was the one who looked back at all the files once again. He had to go scrge
various bureaus to find all these other pieces of evidence that were were widespread over various departments and
agencies. And he tried to consolidate it, put it all together. He ended up reintering witnesses again. Um, and what
started off with just a couple of files ended up being boxes and boxes of files and they really went all out um running
down leads. Um, in 2019, a tipster reported that they had heard stories about men taking apart a car. green
feels that the car looks an awful lot like one that Joseph Ambrose had actually driven at the time and that the
car was pushed into water shortly after uh Mary Kay's murder. This led investigators to search a local
reservoir. It took 5 years to partially to search and then partially dredge this
reservoir and really they got scraps. So, as I was watching this though, I I just like I wondered why that was so
important to them, especially considering that it didn't seem like they got much in the way of evidence.
>> Yeah. You know, um Ted Green was was adamant that finding the car would be the ultimate piece of the puzzle that he
really needed. It was what he viewed as the crime scene. He thought also that the murder weapon, the knife, could
possibly still be in the car. Unfortunately, in this case, they came up with just little scraps of material
which they felt could have been the material from the seats from the inside of the car because it kind of looked
like that, you know, the color of the material they would expect. Um, but they didn't get to the bottom of the
reservoir because they couldn't end up dredging the whole reservoir. Mary Kay's body was exumed for a second
autopsy. Now, you know, after the body was buried for 50 years, I assumed that there really wouldn't be much in the way
of evidence because I assumed there'd be more decomposition. Um, but I want to play a portion of the interview that you
had with Richard Register, the deputy county attorney, and Jennifer Jook, the uh Saunders County Attorney where you
talk about just how well preserved Mary Kay's body was >> when they revealed her after they took
off the um the drapings or whatever that uh thing she had on her. Uh her legs looked like she was in in just the day
before. >> It's remarkable. And >> remarkable. >> The thing that was just frightening is
all is her goosebumps formed on her legs during the autopsy. >> That's what Ted was saying. I did not
know that could happen. Almost as if she was her body was trying to tell you something from the grave.
>> Yeah. Just completely remarkable. I had never heard of that being, you know, a
possibility that, you know, that the body would have goosebumps like that. But apparently according to the
prosecutors they said the medical examiner said that sometimes when a body is reexposed to oxygen that it can have
sort of that that reaction like that. What was fascinating about the second autopsy and what that revealed that
allowed them to get a much bigger clue into who could have done it was they they noticed there were more stab wounds
in the autopsy than was initially reported. And also according to investigators, the manner in which Mary
Kay was stabbed was consistent with how slaughterhouse workers are taught to kill animals. And I bring that up
because Joseph Ambrose worked on the kill floor of a slaughter house. So he knew how to kill animals. He had the
weapons and the knives to kill animals. And the way Mary Kay Hessie was killed, according to the prosecutors and the
medical examiner, upon the second autopsy, they felt that it looked like somebody who knew what they were doing.
Mhm. So then in 2021, Green travels to Ohio now to interview Ambrose again. Um, this guy kind of gets around because
every time they try to track him down, he's living in a in a different state. Do we have any idea just what was going
on in his life over the decades between, you know, Mary Kay's murder and 2021? >> Yeah, I mean, it's it's hard to really
pin it down. Um, we do know that according to authorities, Ambrose had had six wives. He also reportedly was a
truck driver perhaps for some of that time, uh, according to the prosecutors. Um, but when Ted Green goes to interview
him this time, he asked him about claims that people had reported at the time that they had witnessed blood on his car
around the time of the murder. And Ambrose admitted there was blood on his car because he said he probably ran over
a deer or a rabbit, but the blood was reported on the back rear fender. And that is not typically where you run over
an animal. You don't really back up into the animal. You would hit them moving forward. So, the fact that Ambrose said
yes, that there was blood on his car, Ted Green felt that was a revealing part of the interview,
>> right? I I just thought to myself, either a deer, a deer or a rabbit. I mean,
>> yeah, you would think you'd be able to narrow it down and you would remember what you hit.
>> Yeah. If you hit a deer, you probably uh never forgot that there, you know, but
>> there's a lot more damage to the car as well. >> Absolutely. So by 2023, Green feels like
he has compiled enough evidence. He shows his findings to the county attorney and then that's presented uh in
front of a grand jury and the grand jury indictes Ambrose for firstdegree murder
for the murder of Mary K. Uh Hessie. Do we know what the collection of evidence was that convinced the grand jury? So,
it was again Ted Green putting all of the pieces together to to give a fuller picture to this puzzle. He had presented
new witness statements, Ambrose's interviews because he went back to the old interviews and it compared to what
Ambrose was telling him now with the new interview. And then, of course, the evidence of the shoe print. Well, Ted
Green says the shoe prints at the murder scene appear to match Ambrose's size, the size 9 and a half. And also the
pattern was a prisonisssued shoe that Ambrose who had served time. He was on parole at the time had been new to the
town, but he had been given a prisonisssued shoes. So it could have matched the pattern that was found at
the crime scene. So they are preparing to go to trial and then in July of 2025 before the case can uh be heard in a
courtroom, prosecutors reach a plea deal. So Ambrose agrees to plead no contest to the charge of conspiracy to
commit first-degree murder. But because the crime was governed by the sentencing
guidelines in 1969, the charge carries a very light penalty just 2 years behind bars. Ambrose is
sentenced to the maximum. It's 2 years, right? And with the good time sentencing
reduction law, Joseph Ambrose sentence was actually cut in half. So, with time served, he was actually released in
November of 2025, which for the murder that has haunted this town for so long, 55 years, for him to serve just a little
over a year, you know, for the family, it was a real shock and almost a slap in the face. They were not happy about that
whatsoever. They wanted to bring the case forward to a jury. They wanted the case to go forward in trial. But
Ambrose, he said he did take this plea deal because he um because of his age, he was on oxygen. He had some health
issues. He was in his late 70s. He may not have lived until trial. To this day, though, he maintains his innocence. With
this plea deal, he didn't really have to talk about the case at all. He didn't have to address
any of the accusations. He didn't have to reveal any details about the murder. So you can't you can understand why
viewers and I count myself among them would feel like a little unsatisfied with this result. What the prosecutors
told us is while they understand and they see the family's perspective, of course they would have loved to have
been able to have charged him and to really have seen him, you know, go to trial, they do believe Ambrose did this
um as does the family. But the prosecutors really felt that their case faced several challenges. This is 55
years later. The possibility of witnesses not being around much longer, might have even died. Uh prior
statements could be viewed as hearsay and that would be inadmissible in court. You know, the murder weapon also was
never found. There was no DNA evidence and they weren't confident that they were going to be able to get a
conviction from a jury. Ambrose h also had an experienced attorney who was provided by the state. That attorney was
able to get Ambrose the best plea deal possible. It's it's very difficult. Not only is it difficult to investigate
decades old cases, but it's difficult to put together a 48 hours episode. Um so you guys did an excellent job. I really
sort of felt like I was transported kind of back in time and then forward again.
And even though it never went to trial, you know, we did get some answers, >> right? In the end, there is, as you
said, finally an answer and some form [music] of justice for Mary Kay. Hes murder.
>> Absolutely. Um, really interesting hour. Natalie, thank you so much. >> Thank [music] you. And if you like this
episode, please rate and review on Apple Podcast or Spotify.

48 Hours correspondents Anne-Marie Green and Natalie Morales examine the cold case of Mary Kay Heese on Post Mortem. The 17-year-old girl was murdered in Wahoo, Nebraska, in 1969. Here's how the evidence came together to make an arrest over 50 years later.

Crime. Social justice. Impact. "48 Hours" investigates the most intriguing crime and justice cases that touch on all areas of the human experience including greed and passion. "48 Hours," which premiered in 1988, has developed a rich history of original reporting and impact journalism that has helped exonerate wrongly convicted people, caused cold cases to be reopened and solved, and along the way changed lives.

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Brief Summary

Mary K. Hessie's 1969 murder case sees resolution with Joseph Ambrose's arrest and plea deal, but justice feels incomplete for the victim's family.

Key points

The Murder of Mary K. Hessie. A deep dive into the cold case of Mary K. Hessie, a 17-year-old murdered in 1969.
The Shocking Discovery. New evidence and a second autopsy reveal crucial details about the murder.
The Arrest of Joseph Ambrose. After decades, Joseph Ambrose is arrested and charged with Mary K. Hessie's murder.
Ambrose's Plea Deal Shock. Ambrose's plea deal after 55 years leaves the family and community in disbelief.
Maintaining Innocence. Despite the plea deal, Ambrose continues to claim his innocence.
Challenges of Old Cases. Prosecutors face significant hurdles in bringing decades-old cases to trial.

Episode highlights

Episode quotes

This was a real shock to the town of Wahoo.

Natalie Morales discussing the impact of the murder on the community.

1:20WatchFeb 21, 2026

Tension

65/ 100Some tension

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