Multi-barrel laser cannon & tracking
If the scrote can coalign a pack of lasers to point within 10m at 10km, maybe he should be able to get a good job instead of endangering people. If anything, having several lasers just makes him more distinctive once he's nicked.
The beam likely spreads over a substantial distance without a launch telescope. Depending on the coherence, it's reasonable to expect a 0.5-mm aperture giving a resolution like the eye, or about 1m per km. There must have been some tool being used to keep it on you. I'd imagine some loser playing with a nightclub laser mount, or bad luck from an outdoor light show.