Supreme Court justices are to meet privately Friday to weigh whether they will hear a major genetic-privacy case testing whether authorities may take DNA samples from anybody arrested for a serious crime.

The case has wide-ranging implications, as at least 21 states and the federal government have regulations requiring suspects to give a DNA sample upon arrest. In all the states with such laws, DNA saliva samples are cataloged in state and federal crime-fighting databases.

The issue confronts the government’s interest in solving crime, balanced against the constitutional rights of those arrested to be free from government intrusion.

The case before the justices concerns a decision in April of Maryland’s top court, which said it was a breach of the Fourth Amendment right against unreasonable search and seizure to take DNA samples from suspects who have not been convicted.

The Maryland Court of Appeals, that state’s highest court, said that arrestees have a “weighty and reasonable expectation of privacy against warrantless, suspicionless searches” and that expectation is not outweighed by the state’s “purported interest in assuring proper identification” of a suspect.

Maryland prosecutors argued that the mouth swab was no more intrusive than fingerprinting, (.pdf) but the state’s high court said that it “could not turn a blind eye” to what it called a “vast genetic treasure map” that exists in the DNA samples retained by the state.