A Belle Vernon area teenager was shot and killed as he and two companions finished hunting in Rostraver Twp.late Tuesday afternoon;July 2;1974. The victim was identified as Thomas Campbell Hepple;17;of 921 Brown St.;Belle Vernon. He was pronounced dead at the Charleroi Division of the Monongahela Valley Hospital at 7:30 p.m. With the victim at the time were David Michael Macko;18;of Belle Vernon R.D.1 and Joseph Nicholas Hepple;15;of Pricedale. According to authorities;the three boys had just finished groundhog hunting in the vicinity of the Wheeling-Pittsburgh Steel Corp.slag dump off Route 201. As they were unloading the guns;a 12-gauge shotgun discharged striking the victim in the right chest.