Bus driver shot in school lot by someone he says he knows: Did the gunman hold a grudge for six years?

MILWAUKEE (WITI) -- A school bus driver is shot on a playground, and small children were inside the nearby school at the time. The bus driver was listed in critical condition following the shooting, and is now in hiding from the gunman -- who is still on the loose.

The bus driver had to undergo four surgeries following the shooting.

Milwaukee police tell FOX6 News they continue to look for the gunman -- as the bus driver tells FOX6 News he believes the gunman was trying to settle a score that goes back nearly six years.

The bus driver had finished his route, and was headed back to a school near 53rd and Hampton to return the keys.

"He pulled up, he called my name and he shot. He shot me in the back," Stacey Howard said.

Howard ran through the school lot on September 4th as a gunman chased him -- firing shots. Then, Howard jumped a fence and fell to the ground in a nearby lot.

"When I fell to the ground, he stood over me and shot three or four more times. One went into the chest. A few went into my arm," Howard said.

At that moment, Howard says he realized who the gunman was. Howard says it was someone he knew six years ago: Cardel Gregory.

"He also made mention of the fact I shot him when he was 13," Howard said.

A criminal complaint from 2008 confirms Cardel Gregory was 13 years old when he scuffled with his mother at a home near 42nd and Garfield. Howard stopped the fight, and threw Gregory out of the home.

The criminal complaint says Gregory returned with a mob of people, who started banging on the door to get in.

"I shot one time through the door. That was a warning shot, and it just so happened he was the one in front of everybody that was kicking and trying to get into the door," Howard said.

Howard says he believes the boy carried the grudge all these years.

"Those kids were still in that school building. It has a big glass front. You did this in broad daylight during school hour," Howard said.

Milwaukee police say they are actively seeking Gregory.