The caretaker urged the police to set up surveillance equipment at the museum, and when the alarms went off the next day, they stormed the museum, finding a bike, a backpack and absolutely no sign of the would-be gold thief. But luckily, the police had brought along a tracking dog. The dog led its handlers to a wooded area near the museum, where it suddenly lost its shit and started biting the ground. Even weirder, the ground started squealing in pain.
Once the officers had assured each other that no one was having a bad trip, they did a closer inspection and found that what the dog was biting wasn't the ground at all, but the illegitimate love child of Chewbacca and Swamp Thing.
"Arrrrrrr-ghghghghgh!" (Hey, let's see you try to spell the sound Chewbacca makes.)
Actually, it was Liascos, wearing an outfit that would later earn him the nickname "Moss Man." Officially, it's called a ghillie suit -- the type of camouflage that snipers use to blend into the foliage when shooting from grassy knolls. He hadn't yet stolen anything at the moment he was caught, perhaps because he realized the grass suit wasn't a great means of disguising himself once he was inside a rock and mineral museum (dressing up as the Thing from The Fantastic Four would seem like a better choice).
Albeit not the subtle choice.