I think you may not be correct about that.

Currently indefinitely.
Source: http://news.bbc.co.uk/1/hi/uk/7532856.stm

Clealy not the case. You can be perfectly innocent too and get put on the same database as convicted murderers and suspected terrorists. And looking at the figures, it would appear that if are black you are significantly more likely to be added to the DNA database, as well as stopped and searched, pulled over when driving, and - I am sure that statistics will prove - get longer sentences for equivalent crimes.

The Night Stalker was arrested as a result of "good old-fashioned policing" not DNA sampling. But perhaps it could have helped, fair enough.

I still worry about the situation where 75% of young black people are on the DNA database, but only 6% of the white population. I don't think this is racism, but I think we have to ask questions of a society where this happens. I don't believe there are simple answers but I don't believe we should ignore these issues. But perhaps I am still being paranoid.