Lt. Joe Dempsey of the Altadena Sheriff station said that deputies were called to an apparent attempted daytime burglary on Santa Rosa Avenue Wednesday.
A resident called after hearing a knock at the door -- which the resident didn't answer -- followed by some sound in the back of the house. Radio cars and the helicopter responded, but nobody was found.
However, Dempsey said, the screen door at the back of the home had been pried off. He said it fit a common pattern of burglars knocking on doors to see if the house is empty and then attempting to come in through the back. Dempsey speculated that the suspect may have fled when he heard the sirens.
Dempsey said that the sheriff's department is telling residents in these situations to let the person knocking at the door know that someone is in the house -- you don't have to answer the door, but make some kind of noise to let a potential burglar know that the house is occupied.