The guy arrested at 50 Cent's mansion was dressed like a cat burglar, and did his research before the alleged caper, but still got thwarted by a top-notch security system ... TMZ has learned.
Elwin Joyce tried to make his way into the home through the generator room, but set off an alarm that alerted property manager, David Holloway ... according to the police report.
Law enforcement sources tell us Holloway peered out and saw Joyce creeping through a garage, and moving across the mansion's grounds. We're told that's when Holloway ran to his vehicle and drove to the main road to call 911.
We're told Joyce was wearing dark clothes and a dark knit cap when cops busted him. Officers found a printout of directions from a nearby hotel to Fiddy's pad ... indicating the burglary was anything but random.
Joyce was charged Wednesday in Hartford Superior Court and is being held on $125,000 bail.