One of the child victims of a former St. Paul Public Schools janitor is suing the school district and janitor over his years of sexual misconduct with students.

The lawsuit, filed Tuesday in Ramsey County District Court, alleges the district knew about Walter Happel’s inappropriate conduct with students as early as 2003 and failed to take action.

Happel sexually harassed and assaulted the unnamed plaintiff and others from 2011 to 2014, according to the complaint, which seeks more than $50,000 in compensation from each party.

The district “knew, or should have known that Defendant Happel was a sex offender and was a danger to children based upon his conduct that dated back to at least 2003,” the complaint charges.

According to charging documents from Happel’s 2014 criminal case, a Roosevelt Elementary student reported in 2003 that Happel had met him in the restroom and given him candy and a camera they used to take pictures of each other. Police were unable to access the camera images.

In 2011, the plaintiff reported that Happel used the urinal next to him at Linwood Monroe’s grades 4-8 school and that Happel made a comment about his own penis.

In 2012, students said Happel had given them candy, and one boy said Happel had slapped him on the buttocks. School officials spoke with Happel and were satisfied there was no sexual intent.

In 2014, a student said Happel had peeked under and over a bathroom stall the student was using, which led to Happel’s resignation and criminal charges being brought against him.

Several other students then reported unwelcome behavior, and some of Happel’s relatives accused him of sexually abusing them when they were children.

Happel, now 65, pleaded guilty to four charges, including first-degree criminal sexual conduct, and in 2015 was sentenced to 10 years in prison.

School administrators Beth Behnke and Craig Guidry also faced misdemeanor charges for failing to report the 2012 incident, but a judge dismissed the case, finding they had no reason to believe Happel acted with sexual intent.

Behnke and Guidry are named in the new lawsuit but not as defendants.