FORT LAUDERDALE, Fla. — Florida school shooter Nikolas Cruz told a prosecutor’s psychiatrist that he began thinking about mass killing in high school, doing extensive research on past killers to study their methods and mistakes to form his plans, a video showed during his sentencing hearing Monday.

During a prison interview in March, Cruz told Dr. Charles Scott that five years before he killed 17 people at Marjory Stoneman Douglas High School in Parkland on Feb. 14, 2018, he read about the 13 people killed at Columbine High School in Columbine in 1999, which first sparked the idea of ​​his own mass murder. Cruz told Scott how Columbine, the 2007 killing of 32 people at Virginia Tech and the 2012 killing of 12 at a Colorado movie theater played a role in his preparation.

“I studied mass murderers and how they did it,” Cruz told Scott. “How they planned, what they got and what they used.” He said he learned to watch for people coming around corners to stop him, to keep some distance from people when he shot, to attack “as quickly as possible” and that in previous attacks “the police didn’t do anything”.

“I should be able to film people for about 20 minutes,” Cruz said.

Cruz, 24, pleaded guilty a year ago to the murders that took place during the seven-minute attack on February 14, 2018, and the court has only to decide whether he will be sentenced to death or life without parole. Cruz needs a unanimous vote from the seven-man, five-woman jury to receive the death penalty. Anything less and his sentence will be life.

Prosecutor Mike Satz hopes Scott’s testimony will disprove the defense’s claim that Cruz’s mother’s excessive drinking during pregnancy caused him to suffer from fetal alcohol spectrum disorder, setting him up for a lifetime of strange and sometimes violent behavior that culminated in the shooting. . The defense also tried to show that his adoptive mother, Linda Cruz, was distraught after her husband died when Cruz was 5 and never received full treatment from him for mental health issues. She died less than three months before the shootings.

Scott, a forensic psychiatrist at the University of California, Davis, testified Monday that his examination of Cruz, as well as his school and mental health records, did not support the defense’s findings. He diagnosed Cruz with antisocial personality disorder, saying the 24-year-old former Stoneman Douglas student can control his behavior but doesn’t because he doesn’t respect others. For example, Scott pointed to Cruz’s 14 months of incident-free work as a cashier at a discount store as evidence that he could qualify.

He also said Cruz did well in the alternative education classes he took after he was expelled from Stoneman Douglas a year before the shootings, earning a perfect grade in a course he took on violence and guns.

He said Cruz’s behavior spiraled when his girlfriend broke up with him six months before the murder.

Cruz told Scott that the night before the shooting, he adjusted the scope on his AR-15-style semi-automatic rifle to make sure he was shooting accurately. He imagined what the recoil would feel like and how his victims would react. He wore a burgundy polo shirt he had received when he was a member of the Stoneman Douglas Junior Reserve Officer Training Corps so he could blend in with the students when he escaped.

“I couldn’t sleep,” Cruz told Scott.

Satz also replayed videos Cruz made weeks before the shooting in which he talked about how he would carry out the killings and hoped the death toll would be at least 20.

Scott said Cruz told him he specifically chose Valentine’s Day for his massacre because “he has no one to love and love him.”

“It was not a sudden decision. It’s been months in the planning,” Scott said.

Cruz told Scott that he stopped shooting and ran when “I had nobody else to kill.”

The trial, which began on July 18, has been slow – Monday marked only the second hearing in nearly three weeks. Due to Hurricane Yang, the trial was held for only one day last week. It followed a nearly two-week hiatus that came after the defense abruptly rested its case on Sept. 14 after calling only about a third of the 80 witnesses lawyers said they would call. The prosecution then needed time to prepare its rebuttal and call witnesses.

The case is expected to conclude this week. Closing arguments will then be made next Monday, followed by a debate.