Roderick Fountain lost his temper with his 3-year-old son, hit him in the cheek breaking his skull and took the body, wrapped in garbage bags, to a boat ramp at Sheldon Reservoir, a former inmate testified Monday. Fountain, 37, faces one charge of felony murder, accused of causing a death during the course of a felony - injury to a child. The informant, who the Chronicle is not naming, is the second jailhouse snitch to tell police Fountain told them that the body would never be found. Attorneys for Fountain have argued their client is an innocent father who called police when he discovered his son was missing.