Officers found a .40-caliber semi-automatic handgun “in plain view sticking out from underneath the front passenger seat,” as well as a clear, plastic container of alcohol, according to charging documents.
Prosecutors aren’t pursuing charges against the other passenger, a spokesman for the U.S. Attorney’s office said.
Authorities say Lefeged had Maryland State Police purchase paperwork for the pistol but was not authorized to carry the weapon in D.C., which has strict gun laws.
Lefeged, 25, grew up outside of Washington and was a star high school football player in the region. Now entering his third NFL season, he played college football for Rutgers and was signed by the Colts as an undrafted free agent in July 2011. He started four games last season and recorded two tackles and a forced fumble in a playoffs loss to the Baltimore Ravens in January.
The arrest comes as the NFL grapples with gun violence.
Tight end Aaron Hernandez was charged this week with orchestrating the execution-style slaying of a semi-pro football player and was swiftly released by the New England Patriots. Last year, former Kansas City Chiefs linebacker Jovan Belcher fatally shot his girlfriend and then turned the gun on himself.