The San Mateo County Sheriff's Office is warning residents about a rash of 'door-knock' burglaries in residential neighborhoods around San Carlos.
Potential burglars have been approaching homes and knocking on doors to see if residents are home, according to the sheriff's office.
If someone answers the door, the burglars ask for bogus directions or to see someone who doesn't live there.
If no one answers the door, the home is often burglarized.
The sheriff's office is advising residents to call 911 if stranger knocking on the front door seem suspicious.