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A Florida teenager accused of bludgeoning his parents with a hammer before hosting a party at their home believes he has "such a strong defense" that he will reach a plea deal with prosecutors to avoid a life sentence.

Tyler Hadley, 18, awaits trial on charges of first-degree murder in the deaths last July 16 of Blake and Mary-Jo Hadley. He has pleaded not guilty. In jailhouse letters released by prosecutors, he hopes he can avoid prison altogether and be placed in a state hospital.

"I'll get out," he wrote to a friend.

Hadley repeatedly complains of depression in his letters to friends and family. In a letter to his maternal grandparents last November, he wrote that he cries every day, prays for forgiveness and feels bad about how his brother has been affected by the killings.

"I know he misses our parents and I really miss them too," he wrote. "I feel remorse and guilt every day for what happened. I just hope the Hadleys and the rest of our family know the reason why everything happened. I don't want people to think of me as a psycho."

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Hadley doesn't refer to that reason in the letters, but scattered throughout the letters and police documents are possible factors that could be discussed at trial in an attempt to prove insanity.

Relatives told detectives Hadley believed he was fat, likely suffered from bulimia, he questioned his sexuality and gender. Police were told he had been taking human growth hormones and that he was high when he allegedly killed his parents, though it's not clear what drugs he might have been taking. The teen also told a friend he and his father regularly had physical altercations, though that assertion is disputed by many others interviewed by police.

In letters, he told his older brother he would be apologizing for the rest of his life. He vowed to a friend he had changed and no longer would use drugs or alcohol. In a brief February note not addressed to anyone in particular, he offers remorse again.

"This is to all the people who followed my case," he wrote. "I want you all to know I regret what I did but I have found god. I shocked the world and I'm sorry."

Another inmate, however, said Hadley laughed frequently when discussing the case. The inmate, George Brown, told police Hadley had a simple answer when he asked why the parents were killed: "They deserved it."

Hadley's attorney, Mark Harllee, did not immediately return a call seeking comment.

Police have said about 60 people gathered for a party at Hadley's house after his parents were killed, playing beer pong, smoking cigars and drinking. Their bodies were lying in their bedroom. Friends described Hadley as being in a good mood and hospitable.

One friend said Hadley had planned to hold a second party the following night. Instead, police were tipped off, and he was taken to jail.