A Robbinsdale Cooper High School hall monitor who also helped with the football program was charged Tuesday with sexually assaulting a 17-year-old student last week after the girl's father walked in on the man and his daughter naked in her bedroom.

Tajreed E. Rich, 41, of Minneapolis, was charged with third-degree criminal sexual conduct and was in the Hennepin County jail. He was fired from the school Monday.

Robbinsdale police Capt. Jim Franzen said police received a call Friday from the girl's parents the day of the alleged assault, and later arrested Rich.

Rich had been employed at Cooper since January 2011. As a hall monitor, he made sure students safely got to class, school officials said.

An automated voice mail and e-mails were sent to Cooper parents and staff Monday alerting them to the arrest. The last day of the school year was last Wednesday.

"This is a horrible incident, and the district finds acts such as this reprehensible," school officials said in a statement.

Tia Clasen, a Robbinsdale School District spokeswoman, said Rich may also have worked security at football games. The criminal complaint described him as a "staff member" of the football team who also "provided counseling to students." Clasen said Rich may have counseled students informally but was not a counselor at Cooper.

County Attorney Mike Freeman called the case outrageous.

"He's 41, she's 17 ... He's a hall monitor. I mean, the charge here is a position of authority. I think parents have a right to expect when their kids are at school that people employed at that school are not going to mess with their daughters, or sons, for that matter."

Asked about the prospect of other similar cases involving Rich, Freeman responded, "We hope not."

Before working at Cooper, Rich was a volunteer coach of the cheerleaders at Minneapolis North High School, his alma mater. Rich held that position starting in the 2008-09 school year "even though he had no cheerleading experience," according to the school's cheerleader website.

He was first hired by the Minneapolis School District as an educational assistant aide substitute in 1995, according to district spokeswoman Larissa Chinwah, with that contract being terminated in March 1995. He was rehired in the same position in January 1998. In 1999, he was a security monitor. From 2003 until 2010, Rich held positions of youth coordinator, parent liaison as well as coach at North High School, Chinwah added.

According to the criminal complaint, the girl's father arrived home unexpectedly about 3 p.m. Friday and heard sounds from his daughter's bedroom. He opened the door and saw his daughter naked on the bed and Rich also naked and standing over her.The father said he knew Rich and recognized him as being from the high school.

The girl told officers that it was the second time that she and Rich had had intercourse in recent weeks. She also said he had counseled her about relationships with boys.

Rich acknowledged to police the two sexual encounters with the girl, the having taken place at his home in the 2700 block of Knox Avenue N. He also described the girl "as a 'vulnerable student' and stated that he knew better than to have a sexual relationship with a student," the complaint read.

Clasen said the girl was in any special-education program at Cooper. "This person is charged with a heinous crime," she said. "I don't put any credence into what he is saying."

Rich's criminal history in Minnesota is limited to traffic violations. Clasen said the district does background checks on all potential employees before they are hired.

Star Tribune staff writer Abby Simons contributed to this report. Paul Walsh • 612-673-4482