This is the 7th or 8th person they have arrested.
I wonder if they are arresting anyone who refuses to give them a dna sample. As a jehovah witness, he might refuse unless there was a warrant, and the police would get one more easily if he was under arrest.

I do not understand why a specific random check dna sample needs to be kept on a database or even matched against a database - they only need compare the sample against the evidence.
Why dont they just concentrate on solving this crime? They should not be exploiting people's good will.

You would hope that with the man's details being released to the press, the police are very very sure this time. Or will he be quietly released in a few days?