Student enters insanity plea in killing of neuroscience professor

David Jonathan Brown pled not guilty by reason of insanity in the murder of professor Bosco Tjan on Wednesday. He also reaffirmed his not guilty plea in the use of a knife in Tjan’s death.

Brown’s mental state will be evaluated by Risa Grand, a forensic psychiatrist for the Los Angeles County Superior Court and former assistant clinical professor at USC.

Brown, a graduate neuroscience student, is charged with first-degree murder, including a special allegation of using a “deadly and dangerous weapon” to kill Tjan.

If Brown is found not guilty by reason of insanity, he could be sentenced to life in a state mental health institution, according to Deputy District Attorney Beth Silverman. If he is found guilty of first-degree murder, he could serve from 25 years to life in prison. If Brown is found guilty of second-degree murder, he could serve a lower sentence of 15 years to life in prison.

Brown was arrested at the scene of the crime in December, and police said Tjan’s murder was driven by a “personal dispute.” He worked in Tjan’s lab and had taken a leave of absence for “personal reasons” last year, according to the New York Daily News.

Brown’s next preliminary hearing is scheduled for June 21.