A 1994 federal law created a national database in which local , state , and federal law enforcement agencies can compare and share information on DNA matches from convicted felons , but courts have been at odds on just when such samples can be collected and the information distributed . Maryland 's law allows police to take genetic samples from those arrested . A lower - court ruling against a criminal defendant is put on hold . Chief Justice Roberts said there is a ` ` fair prospect '' the high court will uphold the law .
Maryland 's law allows police to take genetic samples from those arrested . A lower - court ruling against a criminal defendant is put on hold . Chief Justice Roberts said there is a ` ` fair prospect '' the high court will uphold the law .