The son of the Dallas police chief suffered bipolar disorder and was abusing drugs before the June shootout that left a Lancaster, Texas, police officer dead, according to a sheriff's department report on the incident.
ABC affiliate WFAA in Dallas has obtained the sheriff's department's final investigation into the incident in June of this year when David Brown Jr., the son of Dallas Police Chief David Brown, shot Lancaster Police Officer Craig Shaw in a Lancaster apartment complex.
"He told [his girlfriend] that his father Dallas Police Chief David Brown, Sr. was against him and believed his grandmother along with everybody else hated him," the report read.
According to WFAA, investigators said Brown's girlfriend "told us that he had been smoking 'WET' [marijuana or tobacco soaked in embalming fluid] the day before. ... He told her he was hearing voices in his head. His behavior was psychotic, paranoid."
Brown had a brief stay at a psychiatric hospital in 2006, when he was diagnosed with bipolar disorder, the report said. He admitted smoking marijuana daily and said he thought God was talking to him.
According to the report, Brown had stopped taking his medication some time before the fatal shootout.
The incident occurred on June 20, when police were called to an apartment complex to investigate the shooting of a man on the sidewalk, now identified as Jeremy McMillan, 23.
When police arrived on the scene, they found Brown trying to get away. Shaw fired more than two-dozen rounds from his AR-15 rifle, but Brown returned fire and hit Shaw in the head, killing him instantly, police said.
Brown was also hit numerous times in the back of the head, shoulders and thigh, and died from his wounds. According to the autopsy, Brown had marijuana and PCP in his system.
There were 11 unread text messages on Brown's cell phone, including one from his girlfriend pleading with him to stop using drugs, according to WFAA.
"Please don't do that stuff babe," she wrote. "I love you and I don't wanna be away from you. But when you're on that I'm deathly afraid of you. I don't like that feeling."
The woman sent the message two hours before the shootout that left Shaw dead.
"I don't think there was anything that could have prevented this other than this individual not having a weapon," Lancaster Police Department Chief Keith Humphrey told WFAA.
Lancaster says its internal affairs investigation will be finished sometime in December. Humphrey said he and his officers still visit Shaw's family on a weekly basis.
Shaw, 37, was married with a 13-year-old daughter and a 7-year-old son when he was killed. He was a five-year veteran of the Lancaster Police Department and the first fatality in the history of the department.
Brown Jr., who has a child, had a criminal record and spent two months in jail after being arrested in 2003 for selling marijuana, according to public records. He pleaded no contest to the charges and received a misdemeanor drug charge.
In a May interview with the Dallas Morning News, Brown Sr. said he was proud of the way his son had handled the situation.
"I'm much more impressed when you make mistakes, how you respond to it," Brown told the paper. "It speaks to the kind of man he is. He continued his education, he's gainfully employed in spite of some of the mistakes that he's made."
Brown Sr. is no stranger to tragedy. In 1988 his longtime police partner was shot to death and in 1991, his younger brother, Kelvin Brown, was killed in the Phoenix area by drug dealers, according to the paper.