FARIBAULT — A former Shattuck-St. Mary’s teacher pleaded guilty Friday to sexually abusing six students at the Faribault boarding school more than a decade ago.

Rice County District Judge Christine Long accepted the plea from Lynn Seibel on Friday.

“This is something I am not proud about,” Seibel said. “I apologize to my family and everyone involved. I’m very, very sorry.”

The 71-year-old entered the plea more than a year after police opened an investigation into his alleged sexual contact with students. Seibel was charged last October with 17 felony counts for alleged possession of child pornography and the sexual abuse of the six male students from 1999 to 2003. He pleaded guilty to one count of second-degree criminal sexual conduct, five counts of fourth-degree criminal sexual conduct and one count of suing minors in a sexual performance.

Seibel could serve less than three years in prison. Attorneys on both sides said he likely will be sentenced to 52 months in prison for the most serious count and several years of probation for the others. However, he will receive credit for the time he spent in jail and could have his sentence further reduced for good behavior.

Seibel taught drama at Shattuck-St. Mary’s from 1992 to 2003 and lived in one of the dormitories. He was hired despite an earlier criminal conviction for lewd conduct.

He left in 2003 after child pornography was found on his computer. Police apparently were not told about that incident, and he wasn’t charged. He had been working as an actor in California before his arrest last year.

The school in 2001 investigated allegations of sexual misconduct by Seibel but said it found no evidence to support the claims.

A Minnesota Public Radio investigation, however, found that several teachers and administrators saw or knew of sexual behavior by Seibel in the dormitory. One former teacher even recalled walking into a “naked dance party” of teenage boys overseen by Seibel. He said he told the headmaster the next day but nothing was done.

In court Friday, Seibel acknowledged his involvement in the dance party. He said boys at the school had a “tradition” of dancing naked in the showers.

“I enhanced that, I didn’t stop it,” Seibel said.

The judge asked, “Did you encourage it?”

“Yes,” Seibel replied.

Shattuck-St. Mary’s still faces a lawsuit filed by attorney Jeff Anderson earlier this month on behalf of a former student who says he was sexually abused by Seibel. The lawsuit accuses the school of negligence. The former student is not among the victims included in the criminal complaint.