I would start with the suspect for whom we have the weakest evidence. Offer them five years in prison for a guilty plea. If they turn it down, make the same offer to the suspect with the second weakest evidence. After one pass through the suspects, repeat the process with a four-and-a-half year deal.
As soon as one takes the deal, publicize like crazy and show film of the perp being taken to his cell.
As more suspects are identified, repeat the process. Continue until public property is safe.
I would try to get suspect 7 to turn. Graham’s mother is so radical he might be willing to take one for the team
It is going to take time to work cases through the courts. Serious charges and high bail bonds are just as effective in the short term. Word gets around to people with poor impulse control that maybe they shouldn't commit criminal acts.