A suspected drunken driver in downtown Petaluma Saturday evening hit a pedestrian and didn't stop, reported police.

The crash was at Petaluma Boulevard North at Washington Street at about 6:16 p.m.

A witness followed the driver, helping police stop a van driven by Timothy Kemp, 50, of Petaluma.

Kemp, who was at Lakeville and D streets, told officers he was on his way back to the crash scene but couldn't explain why he'd driven beyond streets which would have taken him there, reported Petaluma Sgt. Ken Savano.

Inside Kemp's Ford Windstar van officers found a 12-pack of Budweiser beer with one can open and beer inside of a mug and two bottles of vodka, Savano reported.

Kemp had been convicted of drunken driving last spring and his probation demanded he not drink and drive.

The man failed a sobriety test Saturday night and was arrested on suspicion of felony drunken driving causing injury, felony hit and run and violating his DUI probation, Savano said.

The pedestrian hit by the van was Matthew Bushner, 22, of Petaluma. He suffered moderate injuries and was taken to a hospital.

Bushner also was suspected of being drunk, which may have been in a factor in the collision, Savano said.

Kemp was booked into the Sonoma County Jail in lieu of $30,000 bail.

Officers impounded his van for five days – due to the earlier DUI conviction.

Savano asked any witnesses to the collision to contact Officer Chris Ricci at (707) 788-4373.