What is the main character of the four 'Lethal Weapon' films, played by Mel Gibson, called?

Explanation

The main character in 'Lethal Weapon I-IV' is called Martin Riggs. The films in the series were made in 1987, 1989, 1992 and 1998 respectively. Mel Gibson and Danny Glover play the LA cops Martin Riggs and Roger Murtaugh.