According to a police report, the elder Coleman, 81, was having sex with 38-year-old Patrizia Marie Schrag, who was also cited for lewd and disorderly conduct. The St. Paul Pioneer Press first reported the citation. A police spokesman didn't immediately return a call from The Associated Press.
Coleman raised his son in the New York City borough of Brooklyn, and now lives in Minnesota.
"I love my father dearly," Sen. Coleman said in a statement Wednesday. "I do not condone his actions or behavior, and I am deeply disturbed by what I have learned. He clearly has some issues that need to be dealt with, and I will encourage him to seek the necessary help."