The vehicle believed to be involved in the water bottle attacks is a white Toyota Tacoma with black rims.
Authorities are now investigating four other possible cases as more victims have come forward. One of the earliest victims called the California Highway Patrol Friday afternoon.
"Right there, it hit right here, did an arc like this and then spider webbed out," said driver Adam Albritton.
Until Albritton heard about at least five, and maybe as many as eight other attacks, he assumed the water bottle that flew through the windshield of his Fed Ex truck last Tuesday must have been a fluke.
It happened at the corner of West Barham and Dutton avenues in Santa Rosa.
Santa Rosa school bus drivers are on edge, knowing that someone is throwing water bottles at the windows of moving buses and cars.
Emily Keeran got hit Thursday while driving a school bus that, moments later, would be filled with special education students. The bottle shattered her mirror.
"It was like, really like loud crunching sound and I just saw pieces of glass go flying," she said.
"I find it a little bit intimidating, but it's part of the job, I guess. There's stuff to you have to deal with," said school bus driver Mary Hanson.
Two buses have been attacked and one driver was hit by shattered glass in the hand and in the eye.
"She was scared when it happened. It was really loud when it hit and, yeah, so it scared her," said Hanson.
No children were on board when the buses were hit. But, drivers are worried about the attacker striking again. The news is also unsettling to parents.
"It seems really dangerous and scary. I mean, especially because most kids here are little. So, you're driving little kids and that's traumatizing," said one parent.
Investigators say the attacks have happened between Santa Rosa and Sebastopol along Highway 12. Three cars and two buses have been hit. Drivers have been showered with broken glass and terrified by the flying object.
"They'll find him. It's such an obvious thing, I think they'll find him," said Hanson.
"We're going to have to catch them in the act. Somebody is going to have to see this actually happen, get a license plate, get a location; something that we can actually pin an individual to it," said CHP officer Jonathan Sloat.