Adam Leonard Hilliker was an American serial killer active from 1979 to 1990.
Adam was born on May 4, 1960 to Gordon Hilliker, a scientist, and his wife Margaret. Minutes later, his identical twin brother, Jeff, was born. Their younger brother Danny followed seven years later.
His victims were primarily male but included some females, and were of all ages and races. Strangulation was his preferred method of killing.