RIVERHEAD, N.Y. (CBSNewYork) – Closing arguments began Monday in the case of a Long Island man accused of driving drunk and killing a Boy Scout.

The defense calls the death of 12-year-old Andrew McMorris a tragic car accident. But prosecutors say a drunk driver drove off the road, turning a dream day into a nightmare.

Defense attorneys depicted Thomas Murphy as a “compassionate, loving guy who was heartbroken” when he plowed into a pack of Boy Scouts, but say he “was not intoxicated.”

The defense delivered this message to the jury: “It’s not illegal to drink alcohol and drive. It’s illegal to be intoxicated, and he wasn’t.”

MORE: Defense Launches Case In Drunk Driving Trial Of Man Accused Of Striking, Killing Boy Scout

“My client wasn’t even impaired by alcohol. By the time he operated his vehicle, all that alcohol was probably out of his system. You eliminate at a certain rate as well. There’s such a small amount of alcohol involved in this,” defense attorney Steve Politi said.

According to Politi, Murphy “didn’t slur his words” after the crash but was “steady and concerned.”

Murphy drank vodka on the golf course, but not enough to make a 350-pound man drunk, Politi argued, adding the .13 blood alcohol reading that was taken four hours after the crash was not properly analyzed.

MORE: Father Of LI Boy Scout Takes The Stand Against Driver Accused Of Killing His Son

“The reading is wrong,” he said. “That .13 is garbage. It’s garbage. It cannot be trusted at all.”

The defense says the Boy Scouts were “poorly supervised,” saying, “They’re out in the roadway.”

Politi urged the jury to put aside emotion, telling them, “Andrew was a beautiful little boy. That’s not why we are here. We are here to determine if a crime was committed.”

“If they were supervised better, they wouldn’t be on that road. And if they were, they’d be walking on the grass, so and then none of this happens,” Politi said.

Prosecutors called that defense a “false and shocking narrative” of “blaming the Boy Scouts.” They say Murphy “was put on notice by a sober friend… that he had no business driving and he drove anyway. No reasonable person would drive.”

“The only person who was poorly supervised that day was Thomas Murphy,” prosecutors said. “He selfishly rolled the dice, and the children lost.”

Murphy wiped away tears during his first show of emotion in court.

The jury has Murphy’s cellphone videos and texts to review, which the prosecution says shows him slurring his words and drunk texting from the golf course.

After five weeks, the jury will begin deliberations Tuesday.