A teenager charged with murdering his girlfriend's mother and stepfather at their Compton mobile home has an "extremely low" IQ that is consistent with being mentally retarded, an expert testified Tuesday.
Giovanni Gallardo, now 18, had an IQ of 57 when he was evaluated after the killings, placing him within the range of mild to moderate retardation, Dr. Deborah S. Miora, a clinical and forensic neuropsychologist, told the court.
She said his score fell within the range of people who have mild to moderate retardation. People who score as low as Gallardo are easily influenced and more likely to act without considering the consequences of their behavior, Miora testified.
"They are susceptible to the ideas and influences of others," Miora said. "They want friends. They want to be liked."
Miora, who was called by the defense, testified that the evaluation she conducted determines whether a test subject is trying to achieve a lower score. She said her evaluation showed that Gallardo was not doing so.
She said the Social Security Administration also diagnosed Gallardo as mentally retarded when the agency evaluated him when he was 13.
Gallardo was 16 when he allegedly killed his girlfriend's parents in October 2011. Prosecutors allege that both teens took part in the slaying and that they then drove around with the girl's dead mother in the back of a Jeep as they purchased supplies for a Halloween party.
Gallardo is charged as an adult and faces life in prison if convicted.
At the heart of the prosecution's case is a detailed confession Gallardo gave sheriff's homicide detectives in which he admitted strangling Gloria Villalta and stabbing Jose Lara with a knife.
The victims' bodies were found in shallow graves. Lara, 51, was handcuffed and his body covered with a blanket. Villalta, 58, was bloated from decomposition and her head was wrapped in duct tape.
Closing arguments in the trial are expected to begin Wednesday.
Gallardo's girlfriend, Cynthia Alvarez, was convicted earlier this month in both murders.
During her trial, Alvarez, 16, blamed her boyfriend for the crimes. She claimed she did not want her parents dead but did not seek help because she was afraid of her boyfriend, whom she described as abusive.
A jury deliberated for about three hours before convicting her of first-degree murder.