Clarence Williams III, a star of 'Mod Squad,' is dead at 81 The Mod Squad, which ran from 1968 to 1973, was one of the first of its kind a prime-time network series that focused on members of the hippie generation at the same time that it exploited them. by Anita Gates (NYT NEWS SERVICE) .- Clarence Williams III, the reflectively intense actor who starred as Linc Hayes, the young, hip undercover police officer with the perfect Afro and a way with the word solid on ABCs The Mod Squad, died Friday in Los Angeles. He was 81. The cause was colon cancer, his manager, Allan Mindel, said.