The 15-year-old is charged with murdering, molesting, and kidnapping his neighbor. The psychiatrist says Castro wasn't always in control of his own actions.
He says the teenager suffers from social phobia, bipolar disorder, and disassociative disorder -- which means only part of him, was conscious of what he was doing as he molested and drowned Alex Mercado.
There's no question now: Raul Castro killed 4-year-old Alex Mercado.
He admitted as much in taped interviews with detectives and he told a psychiatrist hired as an expert by his own defense attorney.
But the expert says Castro made a statement showing he wasn't all there when he did it.
He admitted as much in taped interviews with detectives and he told a psychiatrist hired as an expert by his own defense attorney.
The psychiatrist gave 52 reasons he believes Castro has dissociative disorder, starting with the teenager's belief that his own father molested him at the age of one.
He said pieces of Castro's mind knew what he was doing, but he wasn't in control.
"Individuals who have the kind of disassociation he exemplified have disengagement between their mental processes, including their emotions and thoughts, and their bodily movements in a way that causes them to act in unexpected ways...ways surprising even to them," Dr. Howsepian said.
The psychiatrist said Castro blacked out on many negative details in his life.
But the prosecutor pointed out Castro remembered the details of what he did when he confessed to detectives the next day.
And the victim's mother told Action News Castro's just looking for an excuse.
"He knew what he was doing and you hear it in his confession," Mindy Mercado said.
Action News also talked to Castro's mother Wednesday, she was shaking from nerves and she said Raul wanted to testify in his own defense, but his attorney didn't want that.
Closing arguments begin Thursday morning.
