As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE CREW REPORTED THAT AFTER TAKEOFF, THEY RECEIVED A BAGGAGE DOOR OPEN INDICATION DURING CLIMB. THE ACFT RETURNED TO FIELD AND LANDED WITHOUT FURTHER INCIDENT. MAINTENANCE FOUND THE AFT BAGGAGE DOOR UNLOCKED AND THE HANDLE UNSECURED. OPS CHECKS WERE PERFORMED ON THE DOOR WITH NO DEFECTS NOTED AND THE ACFT WAS RETURNED TO SERVICE.