PORTLAND, Maine – A marine safety expert says a Massachusetts man was likely operating at 50 to 60 mph when his boat ran over a smaller vessel, killing two people on Maine’s Long Lake.

William Chilcott testified Monday it was the responsibility of Robert LaPointe of Medway, Mass., to stay clear of the vessel he was overtaking on the night of Aug. 11, 2007.

Chilcott says LaPointe was at fault regardless of whether the lights were operating on the victim’s boat. The switch indicated the lights were on, but some witnesses say the lights were off. Chilcott testified he determined the speed based on the distance the boat traveled after hitting land — 160 feet.

LaPointe faces two counts of manslaughter and aggravated operating under the influence. Killed were the two occupants of the smaller boat, Terry Raye Trott of Harrison and Suzanne Groetzinger of Berwick.