Alameda police on Wednesday said they are looking into the past actions of someone they arrested after suspecting they may have been impersonating a federal agent.

Police said they were alerted to a stolen vehicle, around 11:30 a.m. Tuesday, by an automated license plate reader, and that the alert sent officers to the area near Marina Village Shopping Center.

Not long after arriving, the officers spotted the vehicle and contacted the driver.

They then searched the vehicle, and police said they found a gun, counterfeit government identification, drug paraphernalia, and other evidence that led them to believe the driver had been posing as a federal agent.

"Impersonating a government or law enforcement official is not only a serious offense, but it also poses a significant risk to the individual and the public," Alameda police said.

Police said the case remains open, and they are still investigating the driver.