MIAMI -

The trial began Wednesday for a man accused of attacking a veteran Miami-Dade police officer.

With a calm expression and a steady voice Wednesday, detective Carlos Castillo faced the man accused of trying to kill him.

"I have a dent in the top of my head," said Castillo. "I have a scar from my chest line all the way down to my stomach."

Because of his severe injuries, many of Castillo's memories from April 2010 are lost.

According to prosecutors, Michael Robertson ran away from Castillo during a traffic stop, climbed up on a rooftop and threw a 30-pound cinder block onto the officer's head, cracking his skull, and leaving the husband and father of two almost lifeless.

Prosecutors said Robertson then stole the detective's police vehicle and proceeded to run him over with it twice.

Defense attorneys argued that no one ever got a good look at the person who threw the cinder block, and during opening statements, said there are holes in the prosecutors case, specifically with its witnesses.

"It's only when you see all of it that you'll be able to make a decision as to what evidence is credible, and what evidence you can rely on," said defense attorney Charles White.

As for the defendant, Robertson remained somewhat expressionless throughout the day-long process -- but not because of disinterest. He wrote pages and pages of notes, and carefully examined every bit of evidence introduced.