ANNA, TX - Medical examiners determined the shooter in Tuesday’s attack on McKinney Police did in fact commit suicide. Patrick Sharp of Anna died from a self inflicted gunshot wound to the head.

The Collin County Medical Examiner’s office also reported that he had another gunshot wound on his right forearm, but haven’t determined if it was from police fire or self inflicted as well.

9:00 a.m. Tuesday Sharp had set his truck on fire in front of the McKinney Public Safety Building. Police believe he used it to draw people out of the building and then he opened fire on officers. Sharp crossed into a field near Collin College and shot more than 100 rounds from a sniper’s nest on the edge of the woods, about 150 yards away. Sharp was found dead only five minutes later.

But now that McKinney Police know his identity and how he carried out his attack, they’re working on finding out why.

Sharp lived on Quantum Circle in the outskirts of Anna for about five years with long time roommate Eric McClellan. Sharp worked for McClellan’s father part-time at his landscaping firm, Powell Tree Farm. Sharp was also an overnight security guard for Oncor Wires in McKinney.

His roommate’s parents live right behind their home in Anna. They and neighbors said Sharp was always quiet, polite and a hard worker. So that’s why they said it’s difficult to understand his actions and what could have brought him to such desperate measures.

"Everybody wants answers; we want answers,” said Cheryl Cox, the roommate’s mother. “Patrick's parents want answers, my son wants answers, my husband and I want answers, I'm sure his brothers do. You know none of us understand, we can't give you any answers because we don't have any answers. None of us saw it, none of us,” said Cox.

Cox and her husband Bobby knew Sharp well; he was best friends with their son Eric McClellan for several years. They said he seemed happy, even had a trip planned to visit family in Florida this weekend.

"I just feel, just this turmoil that's just roiling away,” said Cox.

You can imagine the shock of his roommate's parents and neighbors when SWAT teams and the Plano Bomb Squad showed up Tuesday evening practically on their front porches.

"I was afraid, my granddaughter was afraid and when I found out what had happened I was totally shocked,” said Cox.

This neighbor doesn't want her identity revealed, but said she knew Sharp from a distance. She is retired and lives at home. She said she saw Patrick everyday leaving and coming home from work and playing with his dogs in the front yard every morning.

"Totally and absolutely out of character for the man that I had watched closely sometimes, you know playing with his animals,” said the neighbor.

She was also watching Tuesday morning before Sharp left the house and headed to the McKinney Public Safety Building. She said he was dressed in nice clothes, pacing in front of his house smoking a cigarette.

"I feel bad for him, for his mental state before this happened, what was he thinking when was pacing the yard,” she said.

Cox doesn't believe he had planned to kill anyone, only himself, because Sharp was a gun enthusiast and an excellent marksman.

"And he was a good shot, and at a 150, 100, 150 yards - he could take out anything he wanted at 200, if he wanted to hit someone he would have hit them,” said Cox.

She speculates as to why Sharp ended up shooting himself in the head, but fully believes it was only a suicide attempt. She said Sharp didn’t have internet at home and never showed signs of radical opinions or affiliations.

"I do not believe in any conspiracy theory, Patrick was not in any way involved with any extra groups, he and my son were best friends they did everything together,” said Cox.

His roommate Eric has been out of town for some time, but will soon come home to an empty house and a broken neighborhood.

"Then this morning his dogs were looking for him.... The dogs came to the end of the driveway looking for him like they always did and he wasn't there,” said the neighbor.

The McKinney Police, Collin County Sheriff's Office, Plano Bomb Squad and the FBI are all working on the case. They recovered at least six or seven guns from Sharp's house on Tuesday and are trying to find out more about his possible motives for targeting the McKinney Police.