Walter J. Happel is charged in eight cases in Ramsey County for allegedly sexually assaulting boys, peeking at students and pressing his penis onto one boy's buttocks in 2010.

Attorneys representing the former St. Paul schools custodian charged in eight sexual misconduct cases plan to invoke the statute of limitations in challenging some of the cases against their client.

Walter J. Happel, 62, of Newport, appeared in Ramsey County District Court Wednesday afternoon in an orange jumpsuit for a pretrial hearing on the eight cases that span 34 years.

Happel's attorneys, Daniel McGarry and Thomas Donohue, didn't specify which cases they'll challenge and declined to comment after the hearing, but Assistant Ramsey County Attorney Andrew R.K. Johnson said he anticipates that two cases from the 1980s will be challenged.

"We knew it would be an issue," said Johnson, who is prosecuting all eight cases.

Happel is charged with several felony counts that range from interference with privacy for allegedly peeking at an 11-year-old boy using a bathroom stall at Linwood Monroe Arts Plus School in St. Paul this February, to first-degree criminal sexual conduct for allegedly raping his son's friend between 1984 to 1988.

The two most serious cases stem from Happel's alleged abuse of his son's friend between 1984 and 1988, and the alleged sexual assault of a relative between 1980 and 1982. Happel is charged with two counts of second-degree criminal sexual conduct in the case involving the relative.

The remaining six cases involve Happel's alleged conduct with young boys at Linwood Monroe from 2010 to 2014, including a 2010 incident in which he allegedly pressed his penis onto one boy's buttocks in the lunchroom.

Happel worked for the St. Paul School District from 1984 until the student reported the February peeking incident, which led to Happel's resignation and criminal prosecution. The February case also led to public tips and reports of Happel's alleged behavior, and seven additional cases were filed against him in May.

Johnson doesn't plan to back down from prosecuting the two older cases, but the complexities and changing nature of the statute of limitations will require research and nuance from both sides.

Minnesota's statute of limitations isn't clear-cut. The statute from the year the alleged crime was committed typically applies to a case regardless of what year that case is prosecuted. But the law has changed multiple times, and some of those modifications affect how the law from previous years are applied.

Further complicating matters is the legal doctrine known as "tolling," which stops the clock from ticking on the statute of limitations. Certain issues can trigger "tolling." Johnson said he has to conduct further research to see whether any "tolling" issues are at play and how the statute of limitations applies in the Happel cases.

"The statute of limitations has changed many times over the years, and it does get very confusing," Johnson said.

Ramsey County District Court Judge Diane Alshouse gave the defense and prosecution until Sept. 12 to file their motions and legal arguments. An evidentiary hearing for oral arguments is scheduled for Sept. 26.

According to charges against Happel in the case involving his son's friend from 1984 to 1988: Happel showered naked with the boy, then 9 or 10, and hit the boy with his penis, fondled the boy and made the boy pose for naked pictures. Happel also allegedly performed oral sex on the boy and forced the boy to penetrate him.

The charges against Happel involving the relative from 1980 to 1982 allege that Happel started abusing the boy when he was 8. Happel allegedly fondled the boy, offered the boy beer and made him watch porn, photographed the boy's genitals and ejaculated on the boy.

The investigations into Happel also led to the charging of an assistant principal with St. Paul schools and a former principal who both worked at Linwood Monroe when allegations surfaced about the custodian. Craig A. Guidry, who is now an assistant principal at Jackson Elementary in St. Paul, was charged in Ramsey County District Court with one out of misdemeanor failing to report the maltreatment of minors.

Former Linwood Monroe principal Beth A. Behnke, who is now principal at Falcon Heights Elementary School in Roseville, faces the same count.

Charges allege that Behnke and Guidry knew about Happel's alleged misbehavior but didn't report a 2012 incident in which he slapped a boy's buttocks and made a sexually suggestive remark. The incident occurred just months after Happel had allegedly followed a different student into the bathroom, exposed his genitals to the boy and made a sexually suggestive remark.

The boy from the 2012 slapping incident is the same boy Happel allegedly pressed his penis onto in 2010.