They could catch them in 2 seconds, Edinburgh University students union, collect information on all the recent students groups that have been planning group discussions or taking part in them about the state of the country, anarchist groups. Subtract from that the ones who's families are high up in society especially in finance. More than likely it was a student, a student from a well off back ground who would have connections through his family to Fred the Shred and known where he lived.
The ones who did it knew he wasn't going to be in
This is true, rich people don't view money or items the same way ordinary folk do, smashing up a merc means its somebody from a rich background. Any other person from a working family wouldn't dream of smashing somebody's car up like that. Well i know i wouldn't. I think the cops know who it is already and are just waiting for the next attack and will be waiting for them.