He published his first book in 1977, The Strayed Sheep of Charum.

In 1989, Roberts published his first mystery SPQR, set in ancient Rome. The book was nominated for the Edgar Award as best mystery of year.

He has lived in various places in the United States as well as in Scotland, England and Mexico. He was in the US Army 1967-70, and did a tour in Vietnam. After he returned, he became a Green Beret.

He lives with his wife in Estancia, New Mexico.

These books were written in the style of Conan series:

Dragonlance Universe

action story about a Crusader returning to Europe to seek vengeance on his father's killers

Mystery series set in Ancient Rome