On February 23, 1971 at 8:25 pm, Detective Wilmoth was shot and killed while conducting a drug raid on a house at 6152 Waterman Boulevard. He entered the house behind a group of people who were visiting the location and identified himself. An occupant of the home, Dennis McMahan, opened fire with a .22 caliber rifle, fatally wounding Detective Wilmoth in the abdomen. Detective Wilmoth was able to return fire and kill the suspect, striking him in the chest and twice in the legs. Detective Wilmouth died at approximately 1:30 am at Deaconess Hospital of massive internal hemorrhaging. Two occupants of the apartment were charged with narcotics violations with quantities of heroin, marijuana and narcotics paraphenalia confiscated from the premises.

Detective Wilmoth was assigned to the Special Operative Deployment Division and had been with the agency for seven years. He was survived by his wife and two sons, Melvin Jr. and Mark.