A man found dead on a Susquehanna State Park trail Saturday was identified yesterday as 60-year-old Richard Edward Lottero, a park volunteer from Havre de Grace, police said. He died of a heart attack, the state medical examiner's office said. A woman hiking on the Heritage Greenway trail spotted his body about 3:40 p.m. and called 911, said Cpl. Ken Turner, spokesman for the Maryland Natural Resources Police. Lottero often helped groom park trails and was believed to be doing so at the time of his death, Turner said.