Feb. 20, 2014 -- A New York City lawyer accused of beating and strangling his girlfriend suffers from "intermittent explosive disorder," according to a defense psychiatrist who has consulted for the "Law and Order" TV series.

Jason Bohn, 35, is on trial for first-degree murder in the 2012 death of Danielle Thomas, 27, a Weight Watchers executive. In an unusual legal turn, Bohn’s attorneys claim the crime stems from the neglect of his mother, publishing executive Maureen O’Connell. O’Connell began devoting herself to her career when Bohn was 10, his attorneys argue – and his those issues triggered his uncontrollable rage.

Forensic psychiatrist Alexander Sasha Bardey, a consultant for the crime drama “Law and Order: SVU,” claims Bohn suffers from “intermittent explosive disorder” and that Bohn “blew up” and had no idea what he was doing when he killed Thomas, the New York Post reports.

Thomas was found in the apartment she shared with Bohn, her body in a tub filled with ice. Officials say surveillance video taken the day of her murder shows the Ivy League-educated attorney buying ice.

Days later, Bohn left a voicemail message for an ex-girlfriend, saying, “Danielle is dead … I don’t remember anything that happened, OK? I think I pushed her.”

Prosecutors also played another message in court – left as Thomas was being attacked on the night of her death, the dying woman repeatedly saying, “I can’t breathe.”

The recording was so troubling, her family had to leave the courtroom when it was played.

If convicted, Bohn could spend 25 years to life behind bars. He's pleaded not guilty and doesn't dispute killing Thomas but he is hoping for lesser manslaughter charges.