I've had the intense, unmitigated pleasure of catching two bike thieves over the years, both were prosecuted after "a scuffle".
One stole the bike I commuted to work on-- I had the front wheel and the seat, and he tried to tell me the bike on his porch, missing the correct front tire and seat, and sporting the custom, hand-lettered logos I had painted on it, was not mine. So I threw him off the porch and beat him with his own wheel and seat, and the cops rolled up to arrest him. I thanked his girlfriend for calling them. The other guy led me on one of the most epic chases ever, and got WORKED, I was pissed that he made me run, and pissed that he bit me, and that he ran again. He got prosecuted to the utmost, the black DA was not pleased that he tried to claim racism. That one was a lot of fun, about 10-15minutes of bare-knuckle brawling and chasing, and more brawling. He was forced to pay all kinds of damages, but I took my payment from him in blood and lumps.
I %$@#(& HATE thieves. Hate 'em.