NEW YORK (CBSNewYork/AP) — A Weight Watchers executive was brutally beaten and strangled in her Astoria, Queens apartment in 2012, and her Wall Street attorney boyfriend was sentenced to life in prison last month for her murder.

As CBS News’ Troy Roberts reported for “48 Hours,” an attorney for Jason Bohn has continued to insist his client was suffering from mental illness at the time of the murder and should not be held responsible. But prosecutors said they have evidence that proves otherwise.

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Bohn, 35, was sentenced on April 15, after being found guilty about a month earlier in the murder of Danielle Thomas, 27, in June 2012.

Thomas’ beaten and bruised body was found in the bathtub in the couple’s Astoria apartment on June 26, 2012. She died of blunt-force trauma to her neck and torso.

Danielle Thomas was tortured and murdered by her boyfriend, Jason Bohn, in 2012. (credit: CBS 2)

Danielle Thomas was tortured and murdered by her boyfriend, Jason Bohn, in 2012. (credit: CBS 2)

Bohn has admitted to killing Thomas, according to his attorney, Todd Greenberg. But Greenberg argued that his client is not a cold-blooded killer.

“There is no doubt that he is suffering from a mental illness,” Greenberg said.

Forensic psychologist Dr. Alexander Sasha Bardey said Bohn’s traumatic childhood was to blame.

“At the age of 9, his own mother abandoned him,” Bardey said. “That leaves a psychological mark.”

Bardey said that childhood experience led Bohn to snap, lose control, and kill the woman he loved.

“Based on mental illness, I believe that Jason Bohn should not be held responsible for murder,” Greenberg said.

But Queens Assistant District Attorney Patrick O’Connor was quick to dismiss that argument.

“It’s absolutely ridiculous to believe that because his mommy didn’t treat him necessarily as well as she should have, that somehow 15 years later, he’s not responsible for the torturing; murder of his girlfriend,” O’Connor said.

Furthermore, prosecutors said they have startling evidence proving that Bohn was not in the throes of a mental illness when he brutally beat Thomas to death.

“He was caught virtually red-handed. We had a tape of him killing her,” O’Connor said.

“You have five seconds,” Bohn apparently says to Thomas in a voicemail recording. “I’m going to let you up, and you need to answer quickly, or else you die.”

The voice mail was believed to have been the result of an accidental dialing of the friend’s number, according to testimony at trial. In the recording, which was played at the trial, Thomas is heard begging Bohn for her life as he strangled her, demanding to know why she had called a certain area code, and saying to her: “This is your life,” to which she replied, “I know.”

Bohn, a University of Florida law school graduate, continued to assault her, saying things such as: “Danielle, you don’t have a lot of time” and ignoring her as she says, “Jason, I can’t breathe.”

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As WCBS 880’s Irene Cornell reported last month, there was much evidence of Bohn’s violent history introduced at trial. Weeks before her death, Thomas had gone to police after a beating had left her with black eyes and on crutches. Bohn had even called her cellphone while she was at the police station and officers heard him threatening to bash in her skull and hunt her down “like a dog.”

Assault charges were pending. Thomas, who worked as a financial analyst with Weight Watchers, had an order of protection when she was killed.

But at his sentencing hearing, Bohn the victim’s mother and grandmother that he and Thomas were best friends and planned to marry.

“Nanna and Mom, I don’t know what to say,” Bohn said, crying. “Whatever you want me to do, I’ll do it.

“I don’t know how this happened.”

At one point, Thomas collapsed at the defense table, weeping and bleeding from the nose.

Thomas’ mother and grandmother spoke at the hearing, the grandmother calling Bohn a “bully” and a “coward.” She, however, said she would forgive him.

“How could you have taken Danielle from me and her mother?” said the grandmother, Juanita Hargrove. “She was the most important person in our lives.

“I’m trying not to hate you, Jason. The Bible says that I must forgive you, and I’m going to.”

The victim’s mother, Janie Thomas-Bright, recalled asking Thomas what she would say if Bohn ever proposed to her.

“Jason, she immediately said, ‘I’d accept’ with a big smile on her face,” Thomas-Bright said. ” … I will never get to be the mother of the bride, helping select the perfect wedding dress for Danielle.”

During the sentencing hearing, Greenberg asked the court to consider Bohn’s terrible childhood, but Queens Criminal Court Judge Michael Aloise was unmoved. Bohn was sentenced to life without parole.

More of Roberts’ report on the case can be seen Thursday on “CBS This Morning,” and at 10 p.m. Saturday on “48 Hours.”

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