Four years on, the Broward County Sheriff’s Office have released drawings made by Cruz in the time he has spent in custody.
The crude stick figure drawings show students at their desks being shot by a grinning gunman.
Other drawings pledge fealty to Satan.
“Lusifer (sic) is my only god,” he wrote in one sketch.
A photo released by the sheriff’s office shows Cruz wrote 666 and drew a pentagram in his cell with his own blood.
“I hate everyone, everything, and anyone,” he wrote in one sketch.
“I never wanted to be alive. I hope I die and never wake up.”
Cruz pleaded guilty to all charges in October last year. A lengthy sentencing hearing is now underway.
The question being weighed up by the jury is whether Cruz faces life in prison or the death penalty.
Cruz’s court-appointed lawyer Melisa McNeill argued his biological mother’s drug and alcohol use while pregnant should be taken into consideration.
“Wounded and damaged people wound and damage other people because they’re in pain,” she said.
“Nikolas was poisoned in the womb.”
The court heard Cruz’s adoptive mother had died four months before the shooting.
Last month jurors were shown a list of Google searches made by Cruz before the massacre.
Cruz searched “how to become a school shooter” and “why I want to kill woman”.
The jury has heard testimony from bereaved family members and witnesses of the shooting.
Over the course of four minutes, Cruz killed 14 students and three staff and wounded 17 people with an AR-15 style semi-automatic rifle.
When the rifle jammed, he escaped the school by blending in with fleeing students.
He was arrested several hours later.
The school itself has remained empty and unused since the day of the massacre, Valentine’s Day, 2018.
The sentencing procedure continues.