Former St. Paul schools custodian Walter J. Happel preyed on innocent children for decades, sexually abusing those closest to him with impunity until an 11-year-old boy reported his strange behavior to a teacher last year.

Three of Happel's victims, now men, watched Thursday as he was finally punished for his crimes and sentenced to 10 years in prison for sexually abusing two of them in the 1980s, and for peeking at a student at a urinal.

Happel, 63, pleaded guilty in March in Ramsey County District Court in three of eight cases against him. He was convicted of four of 13 felony counts.

Five cases were dismissed as part of his plea deal.

His sentencing brought mixed emotions. One survivor, Happel's nephew, said that the sun was finally shining on his face "after all this time." Another, a neighbor boy who was forced into sex with Happel, said the case loosed "destruction" into his life.

When given a chance to address the court Thursday before his sentencing, Happel said, "I'm sorry."

"Who are you sorry to?" asked Ramsey County District Judge Diane Alshouse.

"Everyone," Happel said. "Everyone. I don't know what to say. I really don't."

Alshouse told Happel his pre-sentence investigation showed he didn't understand that adults are responsible for their actions and that children cannot consent to sexual acts.

In March, Happel admitted to sexually abusing the neighbor boy, which led to his most serious conviction — first-degree criminal sexual conduct. He also admitted to fondling his nephew's genitals and to pressing his genitals on the boy's thighs.

He entered an Alford plea — which does not admit guilt, but acknowledges that a conviction is likely — on an accusation that he peeked at a Linwood Monroe Arts Plus student standing at a school urinal in 2014.

As part of his plea deal, Happel agreed to the 10-year term. He must serve slightly more than 6 ½ years before he'll be eligible for parole. He must also register as a sex offender for 10 years.

Chao Xiong • 612-270-4708 Twitter: @ChaoStrib