JEFFERSON COUNTY, Colo. (CBS4) - The First Judicial District Attorney's Office in Jefferson County announced charges against a man accused of sexually assaulting multiple women in the last six months. The DA's office charged Joseph Van Eck with 18 counts of sexual assault, kidnapping, second degree assault and menacing.

Van Eck faced a judge last week and was advised he faces such charges.

The 32-year-old man was arrested on Sept. 18, and remains in jail on a $1 million cash bond.

The DA's office says a young woman called 911 after she was picked up in Denver and driven to the foothills in Jefferson County where she was sexually assaulted. That reported incident happened in April of 2020.

Three more women reported similar crimes in August and September of 2020. Investigators believe there are more victims.

Van Eck is scheduled to reappear in court on Oct. 21 for a preliminary hearing.

Anyone with information about these cases, or who may have been victimized by Van Eck, is asked to contact the Jefferson County Sheriff's Office Tip Line at (303) 271-5612 or Metro Denver Crime Stoppers at (720) 913-STOP (7867).