Two former NYPD detectives believe a Port Chester college student who went missing in 1997 and was later found dead was the victim of a gang of serial murderers who travel the country for victims.

The last time 20-year-old Patrick McNeill was seen alive he was walking out of an upper East Side bar 11 years ago. His body turned up two months later in the waters off Brooklyn.

The detectives who were working the case in 1997 never stopped searching for answers after leaving the force. Now, 11 years later, they claim they have proof McNeill was a victim of a cross-country murder plot executed by psychopaths who belong to the Smiley Face Gang, named after the symbol they leave at the crime scene.

Forensic expert Bob Castelli says the detectives seem to have solid proof to back up their theory. Forty victims discovered in 25 cities all have a common link. They were young, bright, white college students. Police say some of them were drugged before they were drowned.

The detectives say they think they know who McNeill's killers are, but say they just don't have enough evidence to go public.