MINNEAPOLIS (WCCO) — A judge is hearing new evidence Friday in the case against a school janitor accused of inappropriate behavior with several students

Walter Happel, 62, was charged back in March after police say he was caught peeking at an 11-year-old boy in a bathroom at Linwood Monroe Arts Plus School in St. Paul last February. He resigned soon after.

This wasn’t the first time Happel — a school custodian for more than 30 years — was accused of misconduct. According to a criminal complaint, another male student accused Happel of following him into a restroom and making comments about the size of the boy’s genitals, while exposing himself.

After those charges, investigators say several other abuse victims stepped forward.

Happel’s 50-year-old niece testified Friday in the evidentiary hearing, revealing that he touched her inappropriately at least five times when she was in kindergarten.

She says she never reported the alleged abuse, and had only revealed it to her husband.

While prosecutors are hoping Happel’s niece witness will be able to testify at the trial, defense attorneys are questioning her credibility.

The woman has a brain tumor which she admitted affects her memory. Defense attorneys say she could be confusing Happel with someone else.

The assistant attorney for Ramsay County plans to call nine witnesses Friday. A judge will decide what will be allowed at the trial.

Happel has denied the allegations against him. His trial is expected to start sometime in March.

Last summer, two St. Paul school administrators were charged with failing to report prior incidents attributed to Happel.