Four drivers suspected of being under the influence of alcohol or drugs were arrested after they were stopped in a DUI checkpoint, Petaluma police reported Sunday.

Officers operated two checkpoints, stopping people on Sonoma Mountain Parkway at Castle Drive, from 6-9 p.m. Saturday and then across town on Petaluma Boulevard North at Gossage Avenue from 10 p.m. to 2 a.m. Sunday.

In the first checkpoint, 549 vehicles came through and officers screened 544 drivers. They gave 18 drivers a closer look and arrested one, suspected of DUI. Three others were arrested for driving with a suspended license or for being unlicensed, said Petaluma Sgt. Jim Stephenson in a press release.

Later in the night, officers had almost 300 vehicles pass through the checkpoint at the northern end of town and 266 drivers were screened.

Of those, 21 received a more thorough review and three were determined to be under the influence, Stephenson said.

Officers found two people were driving despite suspended licenses and two others were unlicensed. They also were arrested.

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