A bullet that pierced a van's windshield earlier this week was linked Friday to a series of highway sniper attacks (search), bringing the total number of shootings to 21.
The shooting Tuesday expands the sniper's target area: It happened about 15 miles south of where most of the other attacks occurred, authorities said.
Cars, school buses and homes have been shot since May on or near a stretch of Interstate 270 (search) south of Columbus. A car passenger was killed in November.
Ballistics tests on the latest bullet determined that it is one of at least eight to come from the same gun used in the deadly attack, authorities said.
The driver of the van at first thought a rock hit his windshield while he was driving on I-71 on his way to Pennsylvania, authorities said. The driver, identified in a sheriff's report as John Caito of Bridgeville, Pa., later examined the windshield at home and realized a bullet could have caused a hole in the glass.
The damage was reported to Pennsylvania state police, who sent a bullet fragment taken from the dashboard to Columbus investigators.
Investigators believe the shot came from a freeway overpass. The driver did not see anyone along the interstate, sheriff's Chief Deputy Steve Martin said.
"This person is still out there and every time this person or persons does something, the chance of us catching this individual or individuals is greater," Martin said.
No telephone listing could be found for Caito.
Authorities last week received calls from two men claiming to be the shooter. One caller said he would begin shooting at police officers. The other said he had shot a car that day on Interstate 71. No shootings were reported that day.
Investigators do not believe either of the callers were the sniper because they did not provide information that only the shooter would know, Martin said.