POMPANO BEACH (CBSMiami) – Opening statements got underway Monday in the trial of a Pompano Beach teen accused of nearly killing a 15-year-old Josie Lou Ratley when he stomped on her head with steel-toe boots two years ago.

Wayne Treacy, 17, has pleaded not guilty to the attack. His attorney, Russell Williams, has said he plans to use insanity as a defense saying Treacy had Post Traumatic Stress Disorder. “Wayne had a mental disease or infirmaty that he did not knopw right from wrong,” said Russell.

READ MORE: Homeowners insurance changes headed to Gov. Ron DeSantis’ desk

During the prosecution’s opening remarks, Treacy cried as the events of that fateful day were recounted for the jury.

“He grabbed her head by the hair and started smashing it into the surface of the walk,” explained prosecutor Maria Schneider. “You’re going to hear after that he stood up and he began to kick her head as if it were a soccer ball and stomp on her head as if it were putting out a fire.”

Treacy attacked Ratley on March 17th, 2010 at the bus stop in front of Deerfield Beach Middle School after a heated exchange of text messages, according to court records. Both were 15-years old at the time.

Treacy has reportedly admitted that he rode a bike to the school to confront Ratley after receiving a text message from her phone telling him to “go visit” his dead brother. Treacy’s older brother was found dead hanging from a tree in front of a church five months earlier.

Treacy reportedly told psychologist Michael Brannon when he received the text message, “an explosion went off inside” and he put on his brother’s clothes and steel-toe boots, which he used to kick Ratley in the head. Ratley suffered irreversible brain damage from the attack and has no memory of the incident or the text message exchange that instigated it.

His attorney Russell Williams told CBS4 News that Treacy is “nervous but anxious to get the trial over with. Williams said Treacy asked him on Friday, “if it’s alright if he throws up so I hope his mental condition doesn’t interfere with the trial.”

READ MORE: Texas school shooting reignites Florida partisan divide on guns

Williams said he intends to prove to a jury that Treacy suffered from Post Traumatic Stress Disorder related to the suicide of Treacy’s older brother five months before he snapped.

He said Treacy needs mental health treatment not prison time.

“He didn’t know what he did was wrong,” said Williams.

Prosecutors claim Treacy planned the attack, even sending text message to numerous friends beforehand, saying he would be going to jail for killing some.

William Luft was one of Treacy’s best friends. On the stand, he recounted the text he received. He said when Treacy said he was going to kill someone, Luft asked how. He said Treacy responded, “it said ‘I would snap her neck and stomp her skull, fastest way i can think of.'”

Treacy has been held without bond in the juvenile section of the Broward Main jail since he was arrested.

Treacy has been charged as an adult for 1st degree attempted murder which could give him up to 50 years jail time.

MORE NEWS: 2 killed In I-95 Crash In Pompano Beach

Also charged as a juvenile in the attack was Kayla Manson, 14 at the time, who allegedly helped Treacy find Ratley when he arrived at the school. Manson has said she didn’t know what Treacy was planning to do and was charged as an accessory to the crime.