Authorities believe they have a description of the person responsible for a wave of vehicle shootings along northwestern Indiana highways after three more damage reports Friday.

No injuries were reported, and Lake County Sheriff Roy Dominguez said he now believes a pellet gun was the weapon that damaged vehicle windows in 13 attacks reported since July 25.

A motorist who saw one of Friday's midday sniper shootings along Indiana 912 north of Interstate 80/94 gave authorities a description of the shooter and a pickup truck.

All 13 of the shootings have occurred on or near Indiana 912, a four-lane highway known locally as Cline Avenue, which passes through an industrial area shared by Hammond, Gary and East Chicago.

Police did not immediately release the description of the suspect or truck.

The first victim reported seeing a man wearing a trench coat shoot at his vehicle, but until Friday there had been no other witnesses.

Dominguez said earlier this week that investigators were creating a profile of the shooter — someone who is likely a juvenile or young adult.

The shootings began the same day 17-year-old Zachariah Blanton of Gaston was charged with murder in a sniper-style shooting on Interstate 65 in southern Indiana, and authorities have said the latest shootings could be copycat crimes.

Authorities have offered a $10,000 reward and placed portions of Indiana 912 under 24-hour surveillance with unmarked cars and helicopters in hopes of catching the gunman and putting an end to the shootings.