A jury has found Wayne Treacy guilty of attempted murder in the brutal attack on Josie Ratley.
The jury reached the decision just hours after deliberations began Monday morning. Treacy was fingerprinted and led out of the courtroom in handcuffs.
Treacy faces up to 50 years behind bars in the March 17, 2010 attack on Ratley.
"I'm satisfied because justice was done but this is another one of those cases where it's very difficult to be joyful under any circumstances," prosecutor Maria Schneider said. "We have a young lady whose life will never be the same, will never be normal, and we have a young man who has some serious issues who clearly is facing a very very significant and serious sentence."
Schneider said she was in contact with Ratley's mother, who thanked her.
"I know that she is very grateful that the outcome is as it is," Schneider said.
Treacy's attorney, Russell Williams, said he plans to appeal the decision.
"Obviously I'm disappointed, I think a key piece of evidence didn't come into evidence, which was the video interrogation, and I'm hoping that on appeal the appellate court sees that and the conviction gets reversed and we do this again," Williams said.
He said that his 17-year-old client was worried both about his family and Ratley after the verdict.
"He has all these crazy thoughts going through his mind right now, and I'm really concerned about that," Williams said. "He was placed on suicide watch during the trial."
Last week, attorneys for Treacy presented their argument in support of an insanity claim. They claimed Treacy suffered from post-traumatic stress disorder and was not in control of what he was doing at the time of the attack.
Police said Treacy sought out Ratley, who was 15 at the time, after she sent him text messages about his older brother, Michael, who had recently committed suicide. Prosecutors said he punched, kicked and stomped her head with steel-toed construction boots at a bus stop outside Deerfield Beach Middle School.
Ratley suffered severe brain damage in the attack and spent over 40 days at the pediatric intensive care unit at Broward General Medical Center.
Prosecutors said Treacy was in his right mind and knew exactly what he was doing when he attacked her. He has been held without bond since the attack.
After Monday's verdict, Treacy's psychologist said Treacy was in shock.
"He took it very hard, he's still in a state of shock over what's been going on from start to finish with this, so really he was kind of stunned," said Dr. Michael Brannon, who evaluated Treacy shortly after the 2010 incident and was on his defense team.
Brannon said that everyone agreed that Treacy had a mental illness at the time – and the rest became a legal opinion issue.
His lawyer, Williams, said Treacy needs treatment that will not be provided in prison.
"You still have a mentally ill child that the state's doctor and two defense doctors agree has chronic post-traumatic stress disorder, has not been treated for two and a half years, and there is nothing to do for him except throw away the key," Williams said.