Born in Malvern, Arkansas, Collins received a Bachelor of Arts degree from Arkansas Polytechnic College (now Arkansas Tech University) in 1973 and a Juris Doctor from the University of Arizona College of Law (now James E. Rogers College of Law) in 1975.

He was a city magistrate for the City of Tucson Court from 1981 to 1983, thereafter returning to Pima County Attorney's Office as a county attorney until 1985.

On May 11, 1998, Collins was nominated by President Bill Clinton to a seat on the United States District Court for the District of Arizona vacated by Judge William Docker Browning.

Collins was confirmed by the United States Senate on July 31, 1998, and received his commission on August 3, 1998.

[1] On January 11, 2011, following the death of Chief Judge John Roll in the 2011 Tucson shooting, Collins ordered that the judges of the District of Arizona, all of whom knew Roll well, could not preside over the prosecution of the alleged murderer.