Heather Lavelle was an unlikely killer.
But in Summer 2004, a killer is exactly what Lavelle became. In August of that year, she and boyfriend James Savage tortured and beat her ex-boyfriend Christian Rojas to death in his Bensalem apartment.
If not for Bensalem Police Det. Chris McMullin -- who worked as one of the lead detectives on the case, along with two from the Bucks County District Attorney's Office -- Lavelle and Savage may have gotten away with the crime.
McMullin will be detailing the gruesome homicide on the Feb. 17 episode of new discovery+ show "American Detective," launching Jan. 4. Each episode profiles a different murder case from police departments across the U.S.
"This case is the case that has haunted me the most," McMullin, 50, says in the show's trailer. "For me, the driving force is always getting justice for the victim."
The show is hosted by renowned Colorado police detective Joe Kenda, who had solved 356 of 387 cases by the end of his 23-year career.
McMullin isn't far behind. He made national headlines in 2015, when he again teamed up with Bucks County DA detectives to crack the 1984 case of 14-year-old Barbara Rowan.
The homicide was profiled on Discovery Channel's "On The Case with Paula Zahn" in 2018.
McMullin chalks his success up to years of experience, determination and -- maybe most of all -- the fact that he landed his dream job.
"I've pretty much always wanted to go into police work," said McMullin, 50, whose grandmother's house in North Wildwood, NJ was right next to the police station.
"From the time I was a kid I would sit on patio and watch police cars driving in and out. I'd see police officers going in and out.
"I was always enamored by them."
McMullin's first encounter with his heroes happened when he was seven years old. He fell off of his bike, and two officers came over to help him up.
As fate would have it, one of those same officers was the one who interviewed him when he applied to the North Wildwood Police Department.
He got the job.
McMullin started out working with the North Wildwood Police Department in the summers of 1989 and 1990.
In September 1990, he was hired by the Philadelphia Police Department. Two years later, he was hired in Bensalem -- where he's been ever since.
McMullin had been recovering from knee surgery in 2002, and couldn't do much other than sit at his desk, when he was assigned the case that would eventually -- in-part -- define his career.
"She told me to take a look at the 'Rowan Case,'" McMullin recalled. "I was like, 'What is that?'
"She said she did it, but it wasn't even on the computer because it happened so long ago."
McMullin would come to find out that the "Rowan Case" referred to the 1984 rape and killing of 14-year-old Barbara Rowan.
It was a case McMullin felt had to be solved.
"I don’t like loose ends and I don’t like mysteries," he said. "I didn’t like that it was unsolved when I felt it was a solvable case.
"We don’t have the amount of murders they have in Philly, and we certainly don’t have enough where I think we should have cold case murders -- let alone the cold case of a child," he said. "That’s what really pushed me."
McMullin certainly had his work cut out for him. He and investigators in other departments worked on the case for years.
In Spring 2002, McMullin was reading a 1986 interview with a suspect from another case, in another agency, for a different matter.
"The guy started spewing about the Rowan Case," McMullin recalled. "He said someone he knew was a suspect and had been involved."
That's when something clicked for McMullin.
"It just made sense to me," he said. "It lit a fire in me."
"'That's the guy,'" he thought to himself, "'and this other guy are the keys to the Rowan Case.'"
Sure enough, McMullin was right. That "other guy" was George Shaw: The man convicted of raping and killing Barbara Rowan. The "spewing man" was Robert Sanders -- the key witness for Shaw's prosecution.
The case took 13 years, and became widely known as one of the most successful cold cases in the U.S. It has since been featured on multiple television shows and books
The Rowan Case not only earned McMullin recognition for his detective work, but helped refined his skills.
Some of which that lead to the successful prosecution of Lavelle and Savage, he said.
The "American Detective" episode can be streamed through discovery+ on Feb. 17. Discovery+ can be purchased for $4.99 a month.
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