POLSON — A Polson man already registered as a sex offender was back in district court Wednesday morning, this time to answer to three counts of felony sex crimes against minors.

Brian Johnston, 36, pleaded not guilty to the charges, each of which carries a maximum sentence of 100 years or life in prison and a $50,000 fine. Johnston is currently on probation for criminal possession of dangerous drugs.

According to court documents, law enforcement began investigating Johnston after a pre-teen girl reported to them that Johnston had sexually assaulted her.

Local police took the girl and her sister to be interviewed by counselors at First Step Resource Center in Missoula. Court documents state that the older sister told counselors that Johnson made her watch and act out the scenes depicted in adult videos. She indicated that the alleged abuse began in April, about a year after Johnston was released from prison.

After obtaining a search warrant, law enforcement investigated Johnston’s residence. According to court documents, they discovered videos that indicated an interest in young girls and that matched the description of the videos given by the victim.

Based on this evidence, law enforcement arrested Johnston.

The defendant will next appear in court for an omnibus hearing Sept. 21, at 9 a.m. He remains detained.