Most police, RCMP for sure, have a database of graffiti and can either tell who did it, or at least add it into their data and heap on the charges when they're caught.
A couple years back we had some kids constantly cutting the fence on someacreage we had to ride through.
When we caught them, there was 2 kids on each of 2 four-wheelers, no helmets, no boots, no license, no insurance.
When the parents showed up at the 'invitation' of the police they screamed at the cops that we should be charged with 'kidnapping' their kids!
The police just smiled at them and started peeling off tickets while waiting for the tilt'n'load wrecker to haul away the impounded quads.
Stupid does as stupid raises them.