DNA has been such an effective tool for solving crimes that many people are pushing to expand the data bank that holds people’s genetic fingerprints.

A bill has been introduced in the Indiana Legislature, for example, to allow DNA samples to be taken from anyone accused of a felony, convicted or not. The Michigan Senate is debating a bill that also would expand the number of people whose DNA can be dumped into the data bank.

Illinois has a stricter standard, allowing DNA to be taken from some arrestees, but only for more serious crimes.

Now, the question is going to the U.S. Supreme Court, which will take it up this month. The court would be wise to adopt a limited approach, allowing DNA to be collected only from those accused of violent felonies and only if a judge or grand jury has agreed the case has merit.

Many of us would recoil from the idea of entering every newborn into a national DNA database, though that eventually would be a superb tool for tracking criminals.

If we’re law-abiding, our genetic blueprints should be private. In the wrong hands, the potential for misuse of such a data bank is great. It could be used, for example, by employers, insurers or government to weed out people whose DNA is associated with physical or mental health problems.

The problem with collecting DNA from all accused felons is that an arrest is not evidence of guilt, but often based on the judgment of a single police officer.

That’s too low a threshold.

Moreover, it seems unwise to lower standards for DNA collection while not knowing how far science might progress in using our DNA to track us. Last month, people who had anonymously donated DNA to research were surprised to learn geneticists could easily identify who they were simply by using Internet sources.

DNA is an excellent crime-fighting tool, but must be used cautiously.

Sun-Times Media