MIAMI (AP) — The teenage killer who lured a friend into a bathroom stall at their suburban Miami middle school 17 years ago and cut his throat has died in prison.

Florida Department of Corrections online records show Michael Hernandez, 31, died Thursday. He had been incarcerated at Columbia Correctional Institute, about 50 miles west of Jacksonville. No cause of death was released, but WFOR-TV said Hernandez was seen on video collapsing, and no foul play is suspected.

Hernandez was serving a life sentence for the February 2004 murder of Jaime Gough when they were both 14-year-old students at Southwood Middle School in Palmetto Bay, just outside Miami.

Hernandez had lured Jaime into a handicapped stall before school with a promise to show him something. He then pulled out a knife, stabbed him more than 40 times and slit his throat. He then hid the knife in a secret compartment in his backpack and went to class.

After Jaime’s body was found, a teacher noticed blood on Hernandez and notified police. It was discovered that Hernandez had become fascinated with serial killers, studying them online. He had made a list of people he wanted to slay, including Jaime. He was found guilty in 2008 of first-degree murder after a jury rejected his insanity plea.

Jorge Gough, Jaime’s father, told the Miami Herald that he was “shocked” to learn of Hernandez’s death.

“I was not expecting this at all,” Gough said. He said he and his wife still talk about their son, who would now be 31, but “not in a sad way.” His son was a straight-A student who played the violin.

“We miss him, and the big question is: What would he be today?” he said.

Hernandez had planned to kill two friends, but Andre Martin got leery when Hernandez tried to lure him and Gough into the stall. The bell rang and the three went to class. The next day, Hernandez killed Gough.

Martin is now a Miami-Dade County police detective. He told the Herald he had mixed feelings about Hernandez’s death.

“My continued condolences for Jaime Gough’s parents, and the entire Gough family,” Martin said. “And the Hernandez family — they were not the ones who committed a crime and they did lose a family member.”