Deputy Luke Gross of the Hancock County Sheriff’s Department was reaching down to pick up a piece of debris from a crash that had happened minutes before when he was fatally struck from behind by a pickup truck, according to a Maine State Police crash report. Gross, 44, was wearing a high-visibility vest and was bending over in the northbound travel lane when he was hit by the truck on Route 3 in Trenton at 5:13 a.m.