Jason Anthony Bulmer

Jason Anthony Bulmer (Howard County Police Department Photo / May 12, 2013)

A Howard County man was sentenced to 30 years in prison Monday for the murder of his teenage girlfriend's father, well-known businessman and blogger Dennis Lane — a slaying prosecutors and defense lawyers say was the result of a toxic teenage relationship steeped in a dark world of violent fantasy.

Prosecutors had sought a life sentence for 20-year-old Jason Anthony Bulmer, who pleaded guilty in February to stabbing Lane to death at his Ellicott City home in May 2013. While calling the crime "perverse, sadistic and dark," Judge Timothy McCrone said he believed Lane would have shown mercy toward his killer, whom a defense lawyer and witnesses described as an intellectually limited man with childlike attributes.

McCrone technically sentenced Bulmer to life in prison with all but 30 years suspended.

Bulmer struggled at Mount Hebron High School, where he met Lane's daughter, Morgan Lane Arnold. Both were lonely teens who were in special- education classes, according to court testimony. Bulmer's defense and county prosecutors say Arnold, who was 14 at the time of the murder, wanted Bulmer to kill her father.

Arnold's attorney, Joseph Murtha, declined to comment on the claims that Arnold manipulated the slow-learning Bulmer or was more authoritative in their relationship. Murtha said his client is scheduled for a court hearing next week, where he will argue that her case should be transferred to juvenile court.

During Bulmer's sentencing McCrone said Lane "was an extraordinarily good man."

"And I can't help but believe on some level that he would be the first to advance the argument that some charity might be appropriate, given the defendant's circumstances and his own daughter's special circumstances," he said.

Bulmer did not show emotion in the courtroom as his mother, Heather Bulmer, and Lane's partner, Denise Geiger, wept throughout the proceedings.

Prosecutors pored over more than 1,000 pages of transcripts from the young couple's electronic communications, which began in November 2012, said prosecutor Danielle Duclaux.

Their friendship "started off innocently enough," Duclaux said. Both had a fascination with anime, vampires and other fantasy characters.

The relationship quickly turned serious, taking a dark turn that mixed violence and sex, she said. Early on, Morgan told Bulmer she had a problem with her father — who did not support the teens' relationship — as well as her mother and the staff at school.

"There was always death to the person they didn't like," Duclaux said. "They could never just say, 'I'm mad at them.'"

Bulmer was infatuated, she said, and killed Lane to please his girlfriend.

Bulmer's public defender, Janette DeBoissiere, told the judge that Bulmer "is not a typical murderer." A few days after his arrest, he told his mother he wanted a stuffed animal from his home, according to a jailhouse phone recording played in court Monday.

His mother told the court that Bulmer struggled to learn in school but was never violent.

"I had no idea that any of this was going on, on their computers," Heather Bulmer said of her only child's dark communications with Arnold. "He doesn't talk a lot. He doesn't express a lot. But I know that he has love in his heart. And I know that he's sorry for what he's done."

Jason Bulmer said in court that he was "very sorry for killing Dennis."

"I just wish in my heart that I didn't do it, because it hurt a lot of people," he said.

The judge also heard from Lane's loved ones, who described him as an exuberant man who enjoyed being involved in the community and was devoted to his family. Lane worked in commercial real estate. He ran a blog called "Tales of Two Cities" about local issues in Ellicott City and Columbia, and hosted a podcast called "And Then There's That."

He lived with Geiger, building the home that would become the site of his death. Both had children from previous relationships.