Vigilantism does nothing to help. It's a group of people setting themselves apart as authorities (playing god).

To do something about the problem of crime, as Azizi has said, become active in local organizations such as Neighborhood Watch (here in the States) or taking political action.
Decry violence whenever and wherever it occurs.

Azizi, a Langston Hughes quote: "Cheap little rhyme to cheap little tune is sometimes as dangerous as a sliver of a moon. Cheap little tune to cheap little rhyme will cut a man's throat sometime."

Frank