DALLAS -- The defense team in the murder trial of Delvecchio Patrick began its case in court Thursday.
Patrick is accused of killing his ex-wife Deanna Cook in 2012 while she was on the phone with 911.
The Defense plans to paint Cook as a drug user who suffered from mental disorders and was prone to violence.
The first witness called to the stand Thursday was a Cedar Hill police officer. He testified that in 2010 he arrested Deanna Cook for aggravated assault against Delvecchio Patrick when the couple had a violent fight.
Cook stabbed Patrick with a small object resembling an ice pick. Cook also suffered injuries that day and was strangled.
The officer testified he was worried about Cook's safety because of the violent nature of the couple's relationship.
Another expert also took the stand, telling the jury that she did a psychological autopsy on Cook and determined she was Bipolar, Schizophrenic and abused drugs before she died.
Defense attorneys say Cook had a history of going into a catatonic state while on PCP and was prone to violence.