COLFAX – A convicted felon was found driving with an improvised firearm in Placer County, deputies say.

The Placer County Sheriff's Office says, back on Jan. 20, a deputy pulled over a pickup truck that had expired tags in Colfax. Laura Massey, a 38-year-old convicted felon, was identified as the driver.

Shortly into the traffic stop, the deputy says Massey admitted to having a hidden firearm.

The weapon, a "zip gun," was found under her arm. Five .22-caliber rounds were also discovered, the sheriff's office says.

Massey was arrested and is facing charges related to possession of a firearm, along with two other misdemeanors.

Commonly known as "zip guns," the sheriff's office notes that improvised firearms aren't always immediately recognizable as a weapon but are potentially deadly nonetheless.