A man accused of leading his two sons in a series of Pikes Peak area bank robberies was convicted by a jury Tuesday in 18 of the 20 counts he faced in the case, according to the Fourth Judicial District Attorney's Office.

Brock Butson, 52, was connected to nine bank robberies and one attempted robbery spanning four months in Colorado Springs and Monument between May and September of last year.

Prosecutors said Butson's two sons, Nicolas, 20, and Braden, 24, took turns robbing banks while their father drove the getaway vehicle.

In court, the younger Butson brother blamed his father for getting him hooked on heroin and methamphetamine before spurring him and a his brother to participate in the string of drug-fueled bank heists.

On Jan. 13, Nicolas Butson was sentenced to four years in prison after pleading guilty in November to three of the nine robberies and one attempted robbery. On Jan. 21, Braden Butson was sentenced to serve two concurrent six-year terms in prison and three years of probation for eight robberies and one attempted robbery. He also pleaded guilty in November.

Brock Butson will appear again in court on July 14.