All three state judges in St. Charles Parish have recused themselves in the case of a Destrehan High School teacher accused of having sex with a 16-year-old student, leaving the parish to call in an ad hoc judge to handle the proceedings.

Judge Emile St. Pierre had to step aside because he is the father of the defendant, Shelley Dufresne, one of two teachers now accused of having sex with the same student.

Both of St. Pierre’s colleagues on the 29th Judicial District Court bench in Hahnville have decided to take themselves off the case, as well.

Dufresne, 32, was arrested Sept. 30 by the St. Charles Parish Sheriff’s Office and booked on one count of carnal knowledge of a juvenile stemming from an alleged sexual encounter with the teen at a home in Montz. A day later, she was arrested again, along with 24-year-old Rachel Respess, for allegedly having a three-way sexual encounter with the student in Respess’ Kenner apartment after a Destrehan football game last month.

A single-page report on Dufresne’s arrest in St. Charles offered few new details about the allegations, though it notes her birthday is Sept. 12, the same day as the group sex in Kenner is alleged to have occurred.

Dufresne faces criminal proceedings in both St. Charles and Jefferson parishes.

In St. Charles, Judge Lauren Lemmon recused herself shortly after setting Dufresne’s bond, saying in a court filing that “her professional relationship with the defendant’s father could reflect on her ability to be fair and impartial in this matter.”

After Lemmon recused herself, the case was reassigned to Judge Michele Morel. She also recused herself this week, though she insisted in a written order that she “could conduct any judicial proceedings fairly and impartially ... even though Judge St. Pierre is her colleague.”

St. Pierre then recused himself Wednesday, clearing the way for the St. Charles Parish Clerk’s Office to request that the Louisiana Supreme Court appoint an ad hoc judge to hear the case.

Retired Judge Anne Lennan Simon, formerly of the 16th Judicial District Court, has been appointed to hear the case, said Valerie Willard, a spokeswoman for the Supreme Court. The 16th District comprises Iberia, St. Martin and St. Mary parishes.

The court record also indicates that Dufresne may be facing additional charges. In a letter to the court, District Attorney Joel Chaisson II asked Morel to make a quick decision about whether to take herself off the case, noting that “potential additional charges” were being investigated.

Chaisson said his office was waiting on other authorities to complete their investigation but that he “anticipated that charges will be filed in this case.”

A spokesman for the St. Charles Sheriff’s Office said Wednesday that its investigation against Dufresne was ongoing.

Dufresne, who is married and has three young children, graduated from Destrehan High in 2000 and LSU in 2005, according to the school district’s website. She has taught at the high school for 10 years.

Both she and Respess have been suspended from their jobs without pay. They are both due in 24th Judicial District Court in Gretna for a status conference Nov. 17.

Follow Richard Thompson on Twitter, @rthompsonMSY.