PHOENIX -- Vandals smashing out storefront windows have struck 22 times this year in one north valley neighborhood. Over the past few years, there have been dozens of incidents, said police.

Just a couple of weeks ago, Dennis Rusk got a call in the middle of the night, alerting him that someone had shot out his storefront windows. It was the third time his store, ABC Glass, has been targeted.

"You feel kind of violated. You try to keep your place neat and clean for the community. Everybody on the street tries to keep it looking nice -- then someone goes in for the heck of it and breaks your window," said Rusk.

Silent Witness spokesman Sgt. Darren Burch said the vandals are using marbles, of all things, to shoot at the windows.

"It's believed they are using some type of slingshot or wrist rocket-type device to propel these projectiles into the windows," said Burch.

Some businesses, including ABC Glass, Mid-First Bank on East Thunderbird Road, and Buddy Stubbs' Harley Davidson, have been repeatedly hit.

Workers at Buddy Stubbs' said vandals have shot out 14 giant glass panes.

Damages for some businesses have totaled more than $100,000, according to police.

"For someone to do this damage just to be a nuisance... I don't even think they realize the incredible dollar amount," said Burch. "It appears to be vandalism for vandalism's sake."

Most of the crimes have happened at night, but at least one case happened in the afternoon, while a business was open.

A worker said she had to dodge falling glass to avoid being hit.

Police want to catch the vandals before anyone is injured.

Anyone with information about this crime is asked to call Silent Witness at 480-WITNESS. Tipsters could be eligible for a cash reward.