MADISON, Wis. -

Two Madison boys were arrested Friday after police said they admitted throwing baseball-size rocks at cars parked in a lot on Beld Street.

The 12-year-old boys told Madison Police Department that they had been throwing rocks into the lot owned by Schmidt’s Towing at 1621 Beld St. because they were bored. The lot is secured, according to police, but the boys had been able to hit windows on cars parked there from elevated railroad tracks.

The incident is not isolated; Schmidt’s Towing employees told police the vandalism has been an ongoing problem. The 12-year-olds told police they’d been pitching rocks there once or twice a month since summer.

The boys were arrested on suspicion of damaging property and released Friday afternoon.