John Carter seemed desperate to find his missing fiancée.
On the night of August 14, 2011 — less than 24 hours after Katelyn Markham had last been seen in the Cincinnati suburb where she lived — Carter dialled 911 and reported her missing.
In the months and years that followed, he repeatedly provided information to police. He spoke out to local and national media, pleading for her return, and, in one interview, he told NBC’s TODAY show he was still calling her mobile phone daily.
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“That’s all I’ve been doing is hoping,” he said then.
But, last year — more than a decade after Markham’s remains were discovered in a makeshift dump in Indiana — Carter’s portrayal of himself as a desperate partner unravelled with a stunning development: He was indicted on two counts of murder in Markham’s death.
Weeks before his trial was set to begin this June, there was more startling news: Prosecutors had agreed to drop the charge if Carter pleaded guilty to the lesser crime of involuntary manslaughter.
On July 18, a judge sentenced Carter, 36, to the maximum prison term allowed under Ohio law — three years.
In an interview with Dateline, Butler County Prosecuting Attorney Michael Gmoser detailed why he chose to pursue charges against Carter after more than a decade — and why he agreed to drop them in exchange for a plea to crime that carried a far less severe punishment.
“I know that there’s a number of people that will condemn me for taking a plea that only allows them to go to prison for three years,” Gmoser said, adding: “To me, whether it’s one day or six days or six months or six years or 60 years, it was more important to me to get justice by an admission of guilt for Katelyn Markham.”
Carter’s defence team and family wouldn’t comment on the plea agreement. Carter didn’t discuss the agreement at his sentencing; one of his lawyers said his client had taken accountability and responsibility for Markham’s death.
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In an interview with Dateline, Markham’s father, Dave, described the moment he learned of the deal as painful and shocking but said he understood that a single juror could have halted a possible conviction had the case gone to trial.
“There was a chance John could walk, and I didn’t want that,” he said.
The night she vanished
When she vanished, Katelyn Markham, a 21-year-old student known for her bold personality and artistic talent, had dated Carter for five years, and they had been engaged for one. They planned to move to Colorado, and in a media interview shortly after she disappeared, Carter — then a Papa Johns pizza delivery driver — called her “the love of my life”.
In interviews with police, Carter provided his account of their last night together. A friend stopped by the Fairfield home where Markham lived before Carter left for another friend’s gathering, according to video of an interview Carter gave to the Fairfield Police Department. Markham stayed home, Carter told authorities.
Carter said that around 2am, he went to his mother’s home, where he lived, and watched a favorite show before he fell asleep around 4am, according to the video. When he hadn’t heard from his fiancée by the next night, he said, he panicked and dialled 911.
Detectives confirmed that Carter had been at the gathering, according to notes from the police department’s case file, and on his computer they found he had watched episodes of White Collar.
Detectives believed Carter had been accounted for that night, according to a report on the case from the FBI, which Fairfield police had sought advice from.
But years later, an investigator in Gmoser’s office who was re-examining the case found reasons to doubt Carter’s account.
Doubts begin to emerge
One possible eyewitness account came from two teenagers who were in Carter’s neighborhood early August 14, 2011, the night Markham vanished.
After her skeletal remains were discovered at the dump site nearly two years later, on April 7, 2013, the teens contacted police and told them that they’d seen something strange at Carter’s home, according to summaries of their interviews in the case file.
They had snuck out to go to a party, they said, and around 2am, two cars slowly pulled up to Carter’s home, including one they recognised as Carter’s red Ford, the file shows. Neither car’s lights were on. Roughly five minutes later, one of the teens said, Carter’s car emerged from the garage and the two cars drove off, according to the file.
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Rebecca Ervin, the lead detective who originally investigated the case, described their accounts as “suspect,” partly because Carter’s computer activity had established his whereabouts, according to the file.
But investigators in Gmoser’s office uncovered details that challenged that element of Carter’s account, as well: Carter’s online search history from the day he reported Markham missing indicated he’d been looking around the web for synopses of the shows he said he’d watched, Gmoser said.
Gmoser said he believed Carter read the summaries in an effort to build an alibi.
When the investigators in Gmoser’s office re-interviewed the witnesses who said they’d seen Carter’s red Ford without its lights on, they provided the same account they had in 2013, and in Gmoser’s view, what they said they saw that morning was a critical piece of evidence potentially linking Carter to the case.
Ervin was “convinced” that Carter wasn’t involved, Gmoser said. “She was wrong.”
Ervin, who still works for the Fairfield Police Department and has the rank of major, declined to speak with Dateline about the case. In an email, Fairfield’s current police chief, Stephen Maynard, disputed Gmoser’s comments.
Maynard said Carter was never eliminated as a suspect, and he provided what he described as a more accurate statement: “Detective Ervin did not believe there was sufficient evidence to conclude Carter was responsible for Markham’s death,” he wrote.
‘She must die’
By early 2023, Gmoser believed his investigators and prosecutors had assembled a case against Carter that they thought wouldn’t get any stronger. On March 13 of that year, a grand jury indicted Carter on murder charges in Markham’s death. He pleaded not guilty.
During a subsequent hearing in a Butler County courtroom, Gmoser revealed that investigators found disturbing poems in Carter’s journal: “Deep down I love her,” he said Carter wrote. “You want to kill her. But I love her. She must die.”
And: “I know I’ll bury the body in the backyard, no I’ll bury it under the trailer and wait until the grass grows over it and leave before anyone reports it missing.”
In a search warrant unsealed that April, prosecutors identified a possible motive in her death. Even though Carter had described Markham as the love of his life, before she disappeared Markham told a friend that she was tired of her relationship and reconsidering the coming move to Colorado.
“Someone inside John’s core group made the statement to me that if Katelyn was to break up with John, it would be catastrophic to John,” Paul Newton, lead investigator for the Butler County Prosecutor’s Office, told “Dateline.”
Prosecutors also learned that a one-time neighbor of Markham’s — their apartments shared a wall when she disappeared in 2011 — recalled hearing an altercation in Markham’s apartment on the night of August 13, 2011.
According to video of an interview Newton conducted with the woman, she said she heard a woman shout “stop it” on the other side of the wall — then a thump.
Yet all of the evidence investigators had uncovered was circumstantial. There was no forensic, eyewitness or video evidence that provided a direct link between Carter and Markham’s death, Gmoser said. Nor could prosecutors say much about how she was killed.
Even though Markham’s remains had been found and the medical examiner’s office concluded she died by homicide, the officials couldn’t determine a cause of death, according to the case file.
A litany of questions remained, Gmoser told Dateline: Was Markham killed in Indiana? Did she go there voluntarily? Did she leave her apartment on her own?
“Those are all open questions,” he said.
A guilty plea
Gmoser said no one in his office discussed the possibility of a plea deal with Carter’s attorneys. Weeks before his trial was scheduled to begin this summer, a defence lawyer asked prosecutors whether they’d consider allowing Carter to plead guilty to a third-degree felony — involuntary manslaughter, or causing another’s death by means of a misdemeanor crime.
“I told him take it,” Gmoser said. “It was almost that quick.”
He made the decision in only a few minutes, Gmoser said, but it was something that had evolved over months while he examined “every piece of circumstantial evidence on how it would be attacked, how I would’ve attacked it as a defence attorney”.
“I knew what was coming,” Gmoser said.
Because the statute of limitations on other possible crimes, like tampering with evidence or desecration of a body, had passed, manslaughter was the only available charge his office could pursue as part of the agreement, he said.
Gmoser could have required Carter to provide an account of Markham’s death. But that, Gmoser said, would have prompted a negotiation. And he wanted to be certain that prosecutors got a guilty plea, he said.
“I got an acceptance of responsibility,” Gmoser said. “I’ll take that.”
