NOVATO, Calif. -- A known sex offender is raising concerns for parents and police in the North Bay he was spotted loitering close to a Novato elementary school.

Several Novato schools sent out warning letters earlier in the week, making certain parents are aware of the suspicious sighting.

Police said the sex-offender broke no law, however, because he didn't step onto school property, staying just outside off campus grounds.

For parents, though, it was close enough.

Students of Rancho Elementary School returned home on Friday with a warning for their parents. On Wednesday, as class was letting out, a registered sex offender was spotted in the park just a baseball field away. The warning told parents that an alert community member had noticed the man loitering in a nearby creek-bed and immediately called police.

For many, the incident provided a reason to sit down with their children and discuss what to do when approached by a stranger.

“If they come up and say want to go for a ride in my car, say no,” said second-grader Julianne Volpe.

Police say the man, 54-year-old Dale Wright, is a 30-year resident of Novato, who has two felony convictions from 1996 of lewd and lascivious acts with a child under fourteen years of age.

Wright is not on parole, however, and has no restrictions on the distance he must keep from schools.

Police said that he was spotted two years ago attending events at his nephew's middle school, and was warned to stay away.

“In this case we have not been able to prove he was on school grounds,” said Novato police Sgt. Jim Tross.. “We have interviewed everyone in the area at that time, and we do not put him on the school grounds at all.”

Still, with 45 registered sex offenders in the city of some 50,000, police say they understand the public concern and welcome the vigilance.

Many city schools have parks and creeks nearby, secluded enough to provide cover. The Garridos case in Antioch seems to have struck a nerve.

“It's just right there in the consciousness right now,” said Tross. “There are people out there who are a threat to children, and we all have to be responsible for identifying them and getting them out of society.”

KTVU knocked at the home of Mr. Wright, a home he shares, according to the state's Megan's Law registry, with his younger brother, who is also a registered sex offender. There was no response.