The weapon was found Jan. 6 by the daughter of a New York woman vacationing in South Florida, who called the car rental agency then drove to the nearest police station to turn in the gun, the South Florida Sun Sentinel in Fort Lauderdale reported Wednesday.
"We got out of the car, we were kind of freaked out," Judith Fleissig said when when she and her daughter, who was interviewing for a pediatric residency program, found the weapon in a bag. "I didn't want to touch it."
Authorities determined the AR-15 semiautomatic was legally owned and accidentally left behind. The sheriff's report didn't indicate whether the gun was loaded.
The gun belongs to Ryan Tannehill, and the couple called the rental company to report a missing item but didn't specify what, a National Football League source told the Sun Sentinel.
A sheriff's report indicated Lauren Tannehill rented the vehicle Jan. 4 and returned it two hours later to the E-Z Rent-A-Car at the Fort Lauderdale-Hollywood International Airport for a different car. A few hours later, the car was rented to Fleissig.
Charlie Graham, vice president of business development for the car rental agency said it was normal procedure for vehicles to be cleaned between rentals.
"That is part of our normal procedures," he said. "I'm not sure how that could get past."