At his resentencing hearing Monday morning Tyler told a judge he doesn't understand why he killed his parents but said he was sorry.
In 2011, when he was 17-years-old, Hadley murdered his parents with a hammer, piled up household items on their bodies and threw a party at their Port St. Lucie home.
Hadley said words cannot explain the amount of remorse and sorrow for his actions and how they have affected his family and his parents' friends.
"I still don't understand myself and the reasons for my atrocious actions. I really don't know, contrary to what anyone else may tell you. I'm telling you the truth. For me to try and explain would be like making excuses and there is no excuse," Hadley told the court.
He pleaded no contest to avoid trial and was convicted to two consecutive life sentences.
"What I can tell you is how sorry I am. How I wish it never happened," Hadley said.
An adolescent psychologist testified last week that no single factor led Hadley to kill his parents.
Hadley's defense attorney is seeking a 40-year prison sentence while prosecutors are seeking life.
His attorney and the prosecution have until November 9 to turn in their closing arguments.
— Jon Shainman (@JonShainman) October 8, 2018