Nikolas Cruz has pleaded guilty to the murders of 17 people killed in the 2018 high school massacre in Parkland, Florida.
The 23-year-old entered his pleas after answering a long list of questions from Circuit Judge Elizabeth Scherer aimed at confirming his mental competency.
He was charged with 17 counts of murder and 17 counts of attempted first-degree murder for those wounded in the attack at Marjory Stoneman Douglas High School in Parkland, just outside Fort Lauderdale on 14 February 2018.
Cruz pleaded guilty on all counts.
Fourteen of those who died were students, and three were staff.
Relatives of the victims, who sat in the courtroom and watched the hearing online through a video link, shook their heads or broke down in tears as Cruz entered his pleas and later apologised to them for his crimes.
A penalty trial will now determine if he will receive a sentence of death or life in prison without parole.
More on Florida School Shooting
Nikolas Cruz: Man accused of 2018 Parkland school shooting in Florida to plead guilty to 17 murders, lawyers say
Officer who stayed outside during Florida school shooting arrested on child neglect charges
Parkland school shooting suspect: Kill me, I’m worthless
- Florida School Shooting
Judge Scherer plans to begin screening jurors next month in hopes testimony can begin in January.
Cruz’s attorneys announced his intention to plead guilty at a hearing last week.
US school shootings: A history
Tony Montalto, the father of 14-year-old victim Gina, said: “Today we saw a cold and calculating killer confess to the murder of my daughter Gina and 16 other innocent victims at their school.
“His guilty pleas are the first step in the judicial process but there is no change for my family. Our bright, beautiful, and beloved daughter Gina is gone while her killer still enjoys the blessing of life in prison.”
Fred Guttenberg, whose daughter Jaime, 14, died in the shooting, said he had visited her grave this week to ask her for the strength to get through Wednesday’s hearing.
“She was the toughest, wisest person I ever knew,” he said.
“My daughter always fought for what was right. My daughter despised bullies and would put herself in the middle of someone being bullied to make it stop.”
Please use Chrome browser for a more accessible video player
Cruz killed his victims on Valentine’s Day 2018 during a seven-minute rampage through a three-storey building at Stoneman Douglas.
Investigators said he shot victims in the hallways and in classrooms with an AR-15 semiautomatic rifle.
Cruz had been expelled from Stoneman Douglas in 2017 after a history of threatening, frightening, unusual and sometimes violent behaviour that dated back to preschool.
The shootings caused some Stoneman Douglas students to launch the March for Our Lives movement, which pushes for stronger gun restrictions in the US.
Since days after the shooting, Cruz’s attorneys had offered to have him plead guilty in exchange for a life sentence, saying that would spare the community the turmoil of reliving the attack at trial.
But longstanding Broward State Attorney Mike Satz rejected the offer, saying Cruz deserved a death sentence, and appointed himself lead prosecutor.
Mr Satz, 79, stepped down as state attorney in January after 44 years, but remains Cruz’s chief prosecutor.
His successor, Harold Pryor, opposes the death penalty but has said he will follow the law.
Follow the Daily podcast on Apple Podcasts, Google Podcasts, Spotify, Spreaker
Like Mr Satz, he never accepted the defence offer. Doing so as an elected official would have been difficult, even in liberal Broward County, where Democrats outnumber Republicans by more than two to one.
Given Cruz’s guilty plea, his attorneys will be able to argue during the penalty hearing that he took responsibility for his actions.