I'd have a blimmin flat tone too if it were my friend! More than that, I would be on to the police and asking where they are in the investigation and whether they propose actually doing anything further publicly, because one appeal in 15 days is frankly not good enough.
I think his brother and/or other family and friends should contact one of the nationals and put it to them to follow up as a human interest story. So far, this case has attracted really no coverage at all in London, bar the local press.
Given their failings in light of recent events, the police need to start pulling their act together, and showing they are actually doing their job.