(NEW YORK) — A jury will soon determine if confessed Parkland school shooter Nikolas Cruz will be sentenced to death.

Opening arguments begin Monday in the penalty phase of Cruz’s trial. The trial is expected to take several months. At the conclusion, the jury’s decision must be unanimous to sentence him to death.

On Feb. 14, 2018, Cruz, then 19, gunned down 14 students and three staff members at his former school, Marjory Stoneman Douglas High School, in South Florida. He was taken into custody that day.

Cruz pleaded guilty in October 2021 to 17 counts of first-degree murder and 17 counts of attempted first-degree murder.

Cruz said in court last year, “I am very sorry for what I did and I have to live with it every day. … It brings me nightmares and I can’t live with myself sometimes.”

Cruz, the deadliest mass shooter to go before a jury, said in court he believes the victims’ families should be the ones to decide whether he gets the death penalty.

Cameron Kasky, a Parkland student in 2018 and now a gun-reform activist, called the death penalty “barbaric” in a tweet Sunday.

The death penalty “will not bring any of the victims back” and will “create a false sense of Justice, which will only come when the gun manufacturers and the politicians who support them are held accountable,” Kasky wrote.

The “shooter does not deserve to live, but the U.S. government and our ‘justice’ system is incapable of responsibly wielding the power to determine value in life,” he wrote. “It’s the politicians who support the gun lobby that should be held accountable.”

Manuel Oliver, whose 17-year-old son Joaquin died in Parkland, told Miami ABC affiliate WPLG, “I think he should die and I think that is not enough. … Not even the death penalty is enough.”

Fred Guttenberg, who has been fighting for gun reform since his 14-year-old daughter Jaime was killed in Parkland, tweeted Monday, “One week ago today I was at the @WhiteHouse to celebrate @POTUS signing gun safety legislation. Today, I am at the Courthouse for the start of the penalty phase of the criminal trial of the person who murdered my daughter with an AR 15. This is the reality of gun violence.”

“Jaime, I miss you beyond words,” he added in another tweet.

Max Schachter, whose 14-year-old son Alex was killed, tweeted Monday morning, “I love you Alex.”

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