The L.A. County D.A. has rejected the gun case against DaBaby that police have been working on since January 2021 -- when he was arrested in Bev Hills for allegedly having a weapon on him during a shopping spree.

You'll recall ... DB ended up in cuffs right there on Rodeo Drive, and was booked for carrying a loaded firearm.

In the end, the D.A. chose not to prosecute because of a lack of evidence -- which is apparent from the D.A.'s report recounting the incident.

The doc states DaBaby and co. were in a Gucci store, and a security guard says he saw DaBaby lift up his shirt. The security guard claimed he saw something in his waistband resembling a gun, prompting him to call the police.

The crew left, but weren't able to escape Rodeo Drive before a run-in with officers who searched the vehicle and did, indeed, find a gun under one of the seats. When nobody claimed ownership of the gun, cops took DB in based on what the security guard had told them. But apparently, that wasn't enough to file charges.

DaBaby's attorney, Drew Findling, tells TMZ ... "We've been 100% confident in Mr. Kirk's innocence since the day of this incident and are appreciative that the Los Angeles District Attorney's Office has made a similar determination."

Great news for DaBaby, obviously -- but he's not out of the woods ... there's still a looming case over his bowling alley scuffle with DaniLeigh's brother, which was caught on video.

Our law enforcement sources say there's a much stronger chance that case could actually get some real consideration by the D.A.'s Office, considering the evidence already out there ... and we're told a felony assault with a deadly weapon charge is very much in play.

That said ... we're told the cops are somewhat skeptical on that one too due to D.A. George Gascon. It's no secret ... Gascon isn't interested in pursuing low-level crimes in and around L.A. ... something he campaigned on. In other words.