(NewsNation) — January 3 is supposed to be Polly Klaas’ 42nd birthday.

Klaas was kidnapped and murdered in October 1993 in Petaluma, California.

Polly’s dad, Marc Klaas, told “Banfield” on Wednesday that it took his family 20 years to “even accept Christmas again.” He eventually started to appreciate life again and shares his advice to the University of Idaho families on how to cope with unimaginable loss.

“It used to be that the time from the day Polly was kidnapped until after her birthday, that I would have to be on Xanax,” Klaas told “Banfield.” “My wife and I were able to start celebrating the holidays again and doing it without guilt. Time is a manager of grief. And if one is able to hold on, one can turn one’s life around and enjoy.”

Klaas added that those impacted by the Idaho murders have to “trust in law enforcement.”

“It just seems to me that they’re going to be able to solve this case, because it seems like the group of suspects has got to be a small group of people … people that live there, people they knew.”

Klaas established the Polly Klaas Foundation to help stop crimes against children.