Except for the fact that a cheek swab is far more intrusive. This has very little to do with victims given that these are those who have not even been convicted. It works when you have absolute trust in government and the police, but that's rarely the case and is open for abuse. And as we have also seen time and time again, temptation often translates into abuse.
If anything, the taking of DNA is less intrusive than fingerprint taking. A DNA sample involves having a cotton bud gently rubbed on the inside your cheek for about 2 seconds. Having your fingerprints taken requires the person taking them to grab each of your fingers, roll it onto an inked plate and then roll it on a fingerprint form. Then all the fingers are inked together and printed again. The whole process takes 10 to 15 minutes, plus another 5 minutes of cleaning the ink from your fingers.
How is properly regulated DNA retention any more open to abuse than the retention of fingerprints or photographs?
Here is what our own Supreme Court said in dismissing a Human Rights appeal against the retention of post-arrest fingerprints and DNA samples, where the suspect was later acquitted:
"The retention of the fingerprints and samples was objectively justified:
(i) the fingerprints and samples were kept only for the limited purpose of the detection, investigation, and prosecution of crime;
(ii) the fingerprints and samples were not of any use without a comparator fingerprint or sample from the crime scene;
(iii) the fingerprints and samples would not be made public;
(iv) a person was not identifiable to the untutored eye simply from the profile on the database, any interference represented by the retention being minimal;
(v) on the other hand, the resultant expansion of the database by the retention conferred enormous advantages in the fight against serious crime."
The 'trust in government' argument would be appropriate if we were talking about, say, China or Russia, but I think there are sufficient legal safeguards to militate in favour of a criminal DNA database in a western democracy.