Closing arguments began today in the trial of the alleged drunken driver who has been charged with second-degree murder for a fatal crash.

Prosecutors say 34-year-old Michael Grasing was drunk when he drove at speeds close to 90 mph on Montauk Highway in Lindenhurst. He smashed into a car driven by 18-year-old Brittany Walsh, killing her.

Walsh had graduated from Copiague High School two days before the 2012 crash.

According to prosecutors, Grasing's blood alcohol level was at .32, four times the legal limit.

In order to find Grasing guilty of second-degree murder, the jury must decide if he acted with depraved indifference.

In closing arguments today, Grasing's attorney attacked the credibility of one of the witnesses who said he had seen Grasing driving recklessly.

The defense wrapped up its closing arguments at around 4:30 p.m. Monday, and the judge let jurors go home for the night. The prosecution will present its closing arguments in court Tuesday morning.