Judge Martinez is a native of Colorado, having been born in Trinidad and raised in the Denver area. A graduate of the University of Colorado, he served as a Public Defender from 1978 to 1989, directing the Colorado Springs Public Defender's Office for four of those years. He is married and has two children.

In 1989, Judge Martinez was appointed District Court Judge of the Fourth Judicial District. In 1994, he was elevated to the position of Chief Presiding Judge, also in the Fourth Judicial District, a position he currently holds.