Petaluma police arrested a 22-year-old man Friday on suspicion of carjacking a young woman in the middle of the day.

A 19-year-old woman, whom police didn't name, reported that at about 1 p.m. in the 1100 block of B Street, a man opened her car door and forcefully pulled her out.

The unarmed man then drove off in the vehicle. The woman wasn't hurt.

Police searched the area with a dog and the Sonoma County Sheriff's Department helicopter without success. The car was located a block away, said Sgt. Jim Stephenson.

Information found inside the car led officers to a residence in the 4100 block of Petaluma Boulevard North, where they arrested Grant Dolcini.

Dolcini admitted to the theft, Stephenson said, but a motive hadn't been determined.

Dolcini was booked into Sonoma County Jail on $70,000 bail.