RELATED: Police say school bus driver shot on I-35W after crash, 1 in custody

The video shows the suspect in the shooting, 31-year-old Kenneth Lilly, heading north in the left lane while the school bus is two vehicles behind him.

A few moments later, Lilly's car comes to a slow stop. He walks past one car and approaches the passenger door on the school bus.

It's difficult to see what may have prompted such a violent outburst. The suspect paces back-and-forth in front of the bus, and about 10 seconds later, the bus seems to nudge forward.

By the time the cameras zoom in, first responders were already on their way.

The video does not seem to show a fender bender, a fight or even a shouting match.

The Minnesota State Patrol tracks the number of cases involving guns being pointed at people on highways and interstates in Minnesota.

In recent years, those numbers have gone up.

Lilly is expected to be charged Thursday.

The bus driver was transported to Hennepin County Medical Center.

Police are not releasing information regarding injuries. A student on the bus at the time was not hurt.

