NORTHAMPTON - Steven J. Morse should not have been charged in the August 2010 boating death of a 10-year-old boy on Norwich Lake in Huntington, his lawyer said Monday.

Meanwhile, attorneys in the case revealed for the first time that solar glare on the water may have played a role in the death of Augustus "Gus" Adamopoulos of Ludlow.

Attorney Michael Jennings asked Hampshire Superior Court Judge Bertha D. Josephson to dismiss charges against Morse, saying there was insufficient evidence Morse was impaired by alcohol or marijuana when the boat he was driving crashed into a small kayak Aug. 17, 2010, killing Adamopoulos and injuring his father, James Adamopoulos.

Josephson took the matter under advisement, and will issue a decision at a later date.

Morse, 38, of Westfield, has pleaded innocent to manslaughter, homicide by a vessel while under the influence of alcohol and drugs, reckless homicide by a vessel, misleading police and three counts of child endangerment while operating a vessel under the influence. He is tentatively scheduled for trial in January.

Jennings said none of the law enforcement officers who questioned Morse on after the collision reported signs Morse was intoxicated and opted not to arrest him.

Morse passed field sobriety tests, and his blood-alcohol content was measured at 0.064, Jennings said. The legal limit to drive a motor vehicle in Massachusetts is 0.08.

Jennings said Morse admitted to smoking marijuana about an hour before the crash, but told police he wasn't feeling its effects by the time he boarded the boat.

A retired Coast Guard commander testified before a grand jury about the combined impairment effects of marijuana and alcohol, Jennings said, but was not an expert in the subject.

First Assistant Northwestern District Attorney Steven Gagne argued a "modest" amount of alcohol and a "modest" amount of marijuana "can result in a dangerous combination of intoxicating effects."

The collision occurred about 6:30 p.m., a time Jennings and Gagne agreed there was significant solar glare on the lake. Jennings said a state police team reconstructed the crash at the same time two days later and found it impossible to see a kayak in the spot where the Adamopouloses were struck.

Gagne told the judge Morse had driven a boat on the lake hundreds of times and was familiar with the glare at sunset. Morse chose not to reduce speed, figuring he'd be blinded for only a few seconds and didn't want to "diminish the ride" for a waterskier he was towing.