You can conjure many insane possibilities in a future unknown.
DNA could be tested for traits that are "more likely to cause criminality". People with those traits can be more heavily scrutinized and surveiled. Or have their employment opportunities limited.
DNA could be multiplied and planted as evidence.
DNA could be cloned, or used in scientific testing without consent.
DNA could be used for targeted biological warfare.
People leave traces of DNA everywhere they go. Who knows what type of detection mechanisms will exist in the future?
There's also the very likely scenario that a central database like this becomes a prime target and leaks. It's borderline guaranteed.
DNA could be tested for traits that are "more likely to cause criminality". People with those traits can be more heavily scrutinized and surveiled. Or have their employment opportunities limited.
DNA could be multiplied and planted as evidence.
DNA could be cloned, or used in scientific testing without consent.
DNA could be used for targeted biological warfare.
People leave traces of DNA everywhere they go. Who knows what type of detection mechanisms will exist in the future?
There's also the very likely scenario that a central database like this becomes a prime target and leaks. It's borderline guaranteed.