The Associated Press reported that the gunman who attacked a high school in Parkland, Florida, in 2018 returned to court on Monday for the sentencing phase of his case, in which a jury will decide whether he is sentenced to death or life in prison without parole.

In October, 23-year-old Nikolas Cruz pled guilty to 17 charges of first-degree murder for the killings of 14 students and three faculty members at Marjory Stoneman Douglas High School. He is simply appealing his sentence.

A panel of seven men and five women, with ten alternates, will hear the case, estimated to last approximately four months. The trial was expected to commence in 2020, but the COVID-19 outbreak and legal battles delayed it.

A month after the incident, prosecutors announced that they would pursue the death penalty for Cruz.

Monday, the chief prosecutor, Mike Satz, emphasized Cruz's cruelty as he approached a three-story school building and fired his AR-15 semi-automatic rifle along halls and into classrooms. According to the witness, Cruz would return to wounded victims and kill them with a second barrage of gunfire.

Satz characterized Cruz as "cold, calculated, manipulative, and lethal," referencing a video Cruz created three days before the massacre.

"The defendant stated as follows: 'Hello, my name is Nik. In 2018, I will be the next school shooter. My objective is to kill at least 20 people using an AR-15 and tracer shots. It will be a major event, and if you see me on the news, you'll recognize me. You're all going to perish. Indeed, I cannot wait.'"

The FBI confirmed after the incident that it had received a tip that Cruz had a "desire to kill" and access to firearms and may have been planning an attack, but agents did not investigate.

Before the incident, a source close to Cruz called the FBI's tip line and offered information about Cruz's weapons and unpredictable behavior.

The FBI recognized that the tip should have been shared with the FBI office in Miami and examined, but neither occurred.