Would anyone really trust the police to build and maintain a DNA database for every person in this country, as they'd like?

Yes, because the human race simply hasn't been able to function these past few hundred thousand years without a DNA database.

Actually the DNA database is no use for preventing these crimes.

For how long would their information be kept in DNA databases?

We could do, with our software, the national DNA database in three seconds.

It could also provide better management of the state's DNA database.

Once on the DNA database you are criminalized for life.

California currently maintains the third largest DNA database in the world.

There are now several DNA databases in existence around the world.

Beyond that, on a global scale the DNA databases are also quite incomplete.