South Portland police have charged three teenagers with multiple home burglaries as part of an investigation into a rash of 30 break-ins since early July.

Police received a tip Tuesday that led to a series of searches and the identities of the three boys, who are 16 and 17 years old, said Detective Sgt. Steve Webster.

Many of the burglaries happened during the daytime and some at night. In at least one case, a resident was home and sleeping when the burglary occurred, Webster said.

“I think it’s frightening on a couple different fronts,” Webster said. “Anybody who has been the victim of a burglary, while it’s not considered a violent crime in the state system … it is a huge invasion of your privacy.”

The other fear is for the suspects. Many homeowners are armed and, when confronted with a burglar, would shoot.

“What would happen if somebody was home and a 16- or 17-year-old was shot and killed to get $20 to $30? It could happen,” he said.

The 30 burglaries over two months is higher than normal, Webster said. The department responded by assigning additional officers to the case. Police suspected that the offenders might be juveniles using the city’s green belt to access different neighborhoods.

The break in the case came when one of the juveniles attempted to sell a stolen item and police learned about it.

“We recovered one thing, one item of stolen property on one of these individuals, and that basically broke the whole thing open,” Webster said.

The youths would typically knock on doors to make sure nobody was home, then find a way in, usually through an unlocked window or door, he said.

The burglaries occurred across a wide swath of the city, from the intersection of Broadway and Elm Street to the Redbank neighborhood. Police say the juveniles are not necessarily responsible for all of the burglaries over the past two months, but are suspected in many.

Stolen items include jewelry, Xbox game consoles, other electronics and two guitars, he said.

Many of the stolen items have been recovered, Webster said. Police are still trying to sort out the items, which were recovered at the youths’ homes. Some items may have come from car burglaries that were not reported to police, he said.

The three suspects were placed under house arrest Tuesday with conditions they must abide by to avoid being jailed.