A federal appeals court says Border Patrol agents must have reasonable suspicion of criminal activity before conducting a forensic search on an electronic device.

Constitutional law experts say the Friday ruling from the Ninth U.S. Circuit Court of Appeals is a significant victory toward limiting illegal searches and protecting digital privacy.

The case centers on a U.S. citizen whose laptop was seized at the Arizona-Mexico border. After a monthslong review, federal investigators found hundreds of hidden child pornography files on Howard Cotterman's computer.

A district court previously found the search unconstitutional and suppressed the evidence against Cotterman.

But the higher court says federal agents had reasonable suspicion based on a previous child molestation conviction against Cotterman.

Border officials claim they don't need reasonable suspicion to search electronic devices.