The state trooper booked a room and parked his car behind the Fairfield Inn on U.S. 64 behind Wolfchase Galleria on Tuesday night.
He found it ransacked the next morning.
Sources say an AR-15 with three clips, a camera, computer and $1,000 in cash are gone.
Tennessee Highway Patrol is releasing very little information about the crime, stressing it's under investigation. THP has not said whether the trooper violated any protocol.
People in the area tell us they aren't happy another weapon is now on the streets.
"They should have some kind of protocol on how to handle these situation with these weapons," said Jerome McNeal, who lives in the area.
"If it got stolen, it's in the wrong hands," said Deonta Whitemore.
Memphis police say nearly half of the guns stolen this year were taken out of a vehicle.
MPD reports 862 guns were stolen out of cars just this year, already surpassing last year and more than doubling 2013's total, when a state law went into effect allowing gun owners to legally tote their firearms in their car without a state-issued permit.
MPD Director Michael Rallings has said the numbers are growing, with more and more thieves taking advantage of guns left in cars.