SELECT Employees.ID, Employees.FirstName, Employees.LastName,
Employees.IsActive, Employees.IsManager, Employees.HasScanCode,
Employees.ScanCodeID, Employees.ScanBadgeTitle, Employees.ScanCodeLocations,
LEFT JOIN Locations
ON Employees.ScanCodeLocations.Value = Locations.ID
ORDER BY Employees.LastName;
SOLVED! I created another similar form that used a multi-value field And it didn't multiply entries so I compared the two and realized what was wrong.
I had [Employees.ScanCodeLocations.Value] LEFT JOINed to the [Locations] table. Employees.ScanCodeLocations.Value only stores a Location ID so the join was supposed to let me use the name of the location but that was unnecessary. The List Box object allows me to define a row source that links the Location ID to its name so I didn't need the location name in the form's Record Source.
Once I removed the LEFT JOIN between Employees.ScanCodeLocations.Value and the [Locations] table it only listed each employee once. Yay!