Someone fired 12 rounds from a gun while driving through the 600 block of Otsego Street at about 7:40 p.m. Saturday, Havre de Grace police said.
No injuries or property damage was reported from the incident, Officer Jeff Gilpin said Tuesday.
Residents heard multiple gunshots and some thought they heard a vehicle speeding away, Gilpin said.
Police found 12 shell casings from a small-caliber handgun. They canvassed the area questioning residents and looking for damage, but found none.
The casings "would be consistent with somebody firing in the air," Gilpin said.
Police have no suspects and the investigation continues.
"That is going to be a tough one for us," Gilpin said, adding that it was lucky no one got hurt.