Klaas founded the Klaas Kids Foundation in 1994, the year after his daughter Polly was kidnapped and killed, to stop crimes against children.
He had some strong opinions on the case of the Santa Clara County prosecutor.
"There's nothing right that goes on in a situation like this," he told ABC7's Dan Ashley. "He never should've done what he did, he should've completely backed off and let the police do their job."
Watch the video posted above to watch the full interview.