CANTON, N.Y. -- Two retired New York City detectives are investigating 40 river-related deaths across the country. Among the names on the list, is Adam Falcon, that according to Minneapolis TV Station KSTP.

Adam Falcon's body was pulled from the Grasse River, near Canton in 2004. Police ruled that Falcon died of an accidental drowning.

KSTP reports that the retired detectives, Kevin Gannon and Anthony Duarte said due to the timing of the deaths, they believe a group of serial killers may be responsible. They believe the deaths may be linked because of a smiley face found near the scene.

Canton Police Chief, Alan Mulkin says there was no smiley face found in Falcon's investigation. And he says he doesn't know anything about the investigation being conducted by the two retired detectives.