Police believed that 17-year-old Karon Lenihan shot another teen over a long-held grudge. Patrick Hernandez, a Far Rockaway High graduate who was headed to SUNY Cortland, had been walking back from cleaning up a local beach on Thursday morning when Lenihan allegedly jumped out of a car and shot Hernandez in the chest. While the nature of Lenihan's grudge against Hernandez is unclear, the victim's grandmother raged to the Daily News, "I'd like to kill......