Evansville police are warning about illegal devices that can turn handguns into fully automatic weapons.
The warning follows a traffic stop early Saturday that led to the arrest of 20-year-old Jaylin Woods.
Police say they found marijuana and a 9mm bullet on Woods, then found a handgun with a machine gun conversion device, or Glock switch, in the trunk.
A witness also told police she saw Woods holding the modified gun earlier that day.
Glock switches are illegal for civilian ownership under federal law.