You cannot be proved guilty of a crime by staying silent. I don't think people are understanding this.
From what I understand, the OP has zero evidence, linking him to the alleged crime. Zero. Nothing. Nada. Zilch. Correct me if I'm wrong...somebody.
If the only evidence the Police have against you, of causing criminal damage, is you staying silent there is a near 0% chance of you being charged. And if you do get charged, the case will get thrown out of Court, when it is heard.
Judge: Prosecutor can you take us through the evidence against the defendant.
Prosecutor: Your honour, we have no evidence as such, but the defendant did not answer our questions. Based on this, we believe him to be guilty of criminal damage.
If there is no evidence, it is the Police's duty to find evidence. This is their job. So, they must search for witnesses, CCTV and get statements which suggest that the defendant did indeed commit the crime.
The defendant has absolutely nothing to gain by talking. The only chance the Police will have of prosecuting the defendant (due to lack of evidence) is by getting a statement, picking it apart and looking for something he said, which can be used to infer guilt.
If you are suspect, the Police are not your friend. They are basically looking to nail you for the crime. If they can't, then you shall be removed from their enquiries. Remember...this is the job and they must leave no stone unturned.
A court of law doesn't give a damn what the Police "think". The only thing that matters is evidence (statements/witnesses/CCTV, etc). Nothing else. Just because the Police "think" that your silence is an admission of guilt, means nothing. The Judge is also duty bound to not allow personal beliefs to affect his/her final judgement.
The above reason was why OJ Simpson managed to get off on a murder charge. It was so blatantly obvious he did it...but the defence team resisted every argument put forward by the prosecution. The main thing that the defence team had going for them, is that at no stage did OJ admit to murder. Had he given a statement, he would've probably served a very long (possibly, life) sentence. His silence allowed him to walk.
Given that the officer in charge didn't seem too interested in the case, it wouldn't surprise me if nothing is heard about this case ever again. Especially when you consider that most Police forces are going to be a little busy processing cases which relate to the riots.