Phoenix police have arrested Daniel Johnson, 20, and charged him with child molestation and sexual misconduct with a minor.

He's allegedly been assaulting his victims for several years.          

Johnson is accused of molesting two young girls over a seven year period.

Police say he was even employed as a daycare worker, so, what can parents do to keep their kids safe from predators?A sex abuse counselor we talked to said most child molesters look like the trusting guy next door.

She shares tips how not to be fooled.

This is 20-year old Daniel Johnson.

He's accused of molesting two pre-teen girls.

“One of the victims he victimized seven years ago and as recently as two months ago,” Sgt. Joel Tranter said. “That's astonishing, but not surprising; I'd hear it more than I'd like to hear it.”

Dr. Dorthy Neddermeyer is a sex abuse counselor and author.

“Eighty percent of children are sexually abused in family, 20 by someone the child knows, and less than one percent are abused by a stranger,” she said.

She said sexual predators are experts at intimidating their victims, so parents should listen for clues.

“Your child is feeling anxious about being around somebody, a peer or adult, or if they don't want to go to school on a certain day,” she said.

In Johnson's case, he was the girls' babysitter and a longtime family friend, who at the tender age of 13 allegedly began molesting them at the victim's homes.

Police say after seven years of abuse the girls finally blew the whistle.

Before his arrest, Johnson worked at a Central Phoenix child daycare center for six months, where police say he passed his background check.

“Exactly what license he possessed if any, I don't know,” Sgt. Tranter said.

Sgt. Tranter said the daycare is cooperating and stresses no children here were harmed.

Meantime, with kids going back to school, Dr. Neddermeyer encourages kids to stand up to would-be perpetrators.