An 18-year-old man is facing charges that he indecently assaulted an 11-year-old boy in a bathroom over the summer after the child had attended a Somerset Recreation Department event, police said. Kieran Murray of Somerset was working for the department at the time. He is accused of touching the youth inappropriately and threatening to kill him if he told anyone, Somerset police said in a prepared statement. Murray pleaded not guilty Tuesday at his arraignment in Fall River District Court on charges including indecent assault and battery. He was released on $5,000 cash bail, police said.