A former Boulder therapist accused of sexually assaulted two juvenile sisters who were clients about 20 years ago is set for trial.

Mark Hochwender, 72, pleaded not guilty Wednesday in Boulder District Court to two counts of sexual assault on a child by a person in a position of trust — pattern of abuse. Both counts are Class 3 felonies and would fall under Colorado’s indeterminate sentencing law for sex offenses, meaning Hochwender could face up to life in prison if convicted.

He is now set for a five-day jury trial starting Aug. 12, according to online court records. He also has a motions hearing set for May 21.

One count of unlawful sexual contact was dismissed by prosecutors in May.

He remains out of custody on a $25,000 personal recognizance bond.

According to an affidavit, two sisters came forward and told police Hochwender sexually assaulted them while they were children and Hochwender was in his 40s.

Hochwender initially was treating the girls’ father when he became a sort of “family therapist.” He then began nude massages, baths and then sex with the girls that began when they were in middle school or high school.

The sisters said Hochwender “groomed” them, and that they were not aware of the other being abused until they discussed it as adults.

The assaults occurred sometime after August 1999 at Hochwender’s home offices in Boulder and Westminster.

A letter was sent to the Colorado Department of Regulatory Agencies in 2020. According to online records, Hochwender retired in 2021 and surrendered his license rather than fight the allegations of “romantic relationships” with clients.

Boulder police said in 2020 the women also came forward to police, which sparked a “long-term investigation involving multiple families.”

Officials at the time of Hochwender’s arrest said they were concerned there may be more victims, but no further charges have been announced.