State law defines sexual intercourse, in part, as “intrusion, however slight, of any part of a person’s body.”

The girl told her mother they were playing “butt doctor” and told authorities the boy only touched her on the outside of her body, court documents state. A third child, a 5-year-old boy, also was with them, but he did not touch her inappropriately, the girl said.

Judge Leineweber refused to dismiss the petitions, saying the relevant part of the sexual assault allegation is the mother’s observations.

The boy needed only to have penetrated the girl and known she was under a certain age, he wrote, adding, “Even the most immature 6-year-old could appreciate these two concepts.”

Last week, Leineweber found probable cause to proceed with the petitions and ordered a competency evaluation to determine if the boy can understand the allegations and assist in his defense.

But Leineweber also questioned how it could be determined that the 6-year-old was capable of committing a criminal act.

Riniker said she made that determination using her discretion as a prosecutor. She also said she has more information about the boy’s actions than she included in the complaint.