Students gather around a makeshift memorial at E.O. Green middle school, honoring slain school student Lawrence King, 15, who was killed by a classmate because he was gay, in this Feb. 14, 2008 file photo, in Oxnard, Calif.
A psychologist testified Monday that he believes a teenager was in a dissociative state when he pulled a gun and shot a gay, middle school classmate three years ago.
Douglas Hoagland, a defense witness, said defendant Brandon McInerney "snapped" during a computer lab class at E.O. Green Middle School in Oxnard when he heard that 15-year-old Larry King wanted to change his first name to Leticia.
Hoagland maintained McInerney, now 17, had a "transient period of disassociation" from the moment he overheard the name change until his arrest after the shooting.
"He acted without thinking," Hoagland told jurors. "He was not aware of what he was doing."
McInerney, who was 14 at the time of the 2008 shooting, is being tried as an adult and has pleaded not guilty to first-degree murder and hate crime charges.
The trial, which has brought national attention to the issue of violence against gays, is being held in Los Angeles because of intense media coverage in neighboring Ventura County.
Prosecutors allege the slaying was premeditated and that McInerney was fueled by white supremacist, anti-gay beliefs.
Defense attorneys don't dispute their client was the shooter but say McInerney was the product of a violent upbringing and he was unable to harness his anger toward King when he made unwanted sexual advances.
They are hoping a jury will convict McInerney of voluntary manslaughter that carries a 21-year maximum sentence. If convicted of first-degree murder, McInerney could face at least 51 years in prison.
Prosecutor Maeve Fox sought to discredit Hoagland's testimony under cross-examination by pointing out McInerney told a friend he was going to kill King the day before the shooting, and the teen brought a handgun, wrapped it in a towel and hid it in a backpack.
She noted in interviews Hoagland had with McInerney that the teen was intensely fixated on hurting King the night before the shooting.
Hoagland said McInerney's growing anger toward King clouded his thought process, but Fox appeared to have a difficult time believing the defendant didn't know what he was doing.
"Are you saying he lost his mind?" an incredulous Fox asked Hoagland.
"I'm saying in the moment he was disassociated," Hoagland responded.
The defense was expected to wrap up this week and prosecutors could call rebuttal witnesses.