After a decade-long investigation, Suffolk County police have arrested Rex Heuermann in connection with the unsolved Gilgo Beach serial killer case. Heuermann, a married New York architect, was charged with three counts of first-degree murder and had a cache of more than 200 guns in a vault inside his home. The case had remained unsolved since the discovery of four bodies in 2010, and investigators are now trying to determine if the weapons are legally registered. Heuermann's arrest may finally bring the case to a close.