BUFFALO, NY-- A City of Tonawanda man was found guilty in connection with the death of a 16-year-old Lockport teen.

A jury found Timothy Wisniewski guilty of criminally negligent homicide, two counts of Operating a Vessel While Under the Influence of Alcohol, Endangering the Welfare of a Child and Unlawful Possession of Marijuana in an accident that claimed the life of Avery Gardner.

Gardner, 16, was killed in June of 2015 after she stood up while in Wisniewski's boat and hit her head on a pedestrian bridge that crosses Ellicott Creek.

The driver of the boat at that time, Gregory Green pleaded guilty to all charges. He also testified against Wisniewski.

"He failed to perceive the risk that allowing a a boy, a child, who had been consuming alcohol and marijuana, and perhaps some other substances, to operate his boat, which he owned, at a high rate of speed, high rate of speed period, extraordinarily high rate of speed, for where they were and the conditions they were in with a passenger," said Acting Erie County District Attorney Michael Flaherty Monday afternoon.

Investigators said Wisniewski had a blood alcohol level of .13% at the time of the accident, and was also under the influence drugs.

"He was in charge, and he allowed a teenage boy, who had been drinking, to operate a boat at a very high rate of speed in a place normally reserved for kayaking and paddle boats. He was driving a power boat and that girl never had a chance," added Flaherty.

Green faces up to seven years in prison when he is sentenced next month.

Wisniewski faces up to four years in prison when he's sentenced in January.