A very good friend of mine had a similar incident happen a few weeks ago. He's been targetted by local chavs/thugs/scum for quite some time now - break-ins, damage to his car, paint thrown over his windows, general property damage etc. The police are aware of this to the extent that he even had a panic alarm provided last year.
The local scum, however, decided to try to shoot out his back bedroom window recently (where he works on his pc) and left a hole very similar to the one posted above. the glass was toughened luckily or the damage would have been worse.
The police wouldn't even come out to LOOK at the damage nevermind DO anything about it.
The trajectory of the bullet led directly to the backyard of the local yobs.
My friend was asked by the police if he had 'ever considered moving house'