One of the more recent unsolved cases of new deaths popping up still revolves around the "smiley face theory". And it's more gruesome and creepy than you might think. The theory came from two New York City detectives who concluded similarities shared between the 45 deaths of young men.

But, what even is the theory and who started it?

Dating back to 1997, 21-year-old Patrick McNeill was last seen drinking with friends and about two months later his body was found near the entrance to the New York Harbor. Since then, there have been about 40 more murders of drunken, white college-aged males and then dumping their bodies in the water. In most places where the body has been found a graffiti drawn smiley face has been found near the crime site.

The theory originates from New York City detectives, Kevin Gannon and Anthony Duarte. The two detectives concluded that the deaths of at least 45 young men were connected to similar murder cases in the Midwest. In more than a dozen cases a painted smiley face has been found near a body of water where the victim's corpse was dumped.

But most of the deaths have been ruled accidental drownings involving alcohol. Which is highly likely, but for more than 40 college-aged men who all supposedly had an athletic build and academically successful, this theory is a long shot. Smiley faces are common forms of graffiti, murder by drowning is rare.

All those points I can see, but in more than 40 cases that are similar in one way or another, I find it hard to believe they were all "accidental". Murders surrounding the "smiley face theory" have even made a recent return. In 2016, a 22-year-old college student went missing after spending a night at a bar and a month later police members pulled his body out from the Charles River.

The retired detectives, Duarte and Gannon have claimed that the Smiley Face Gang had struck at least 25 cities in 11 states with a smiley graffiti drawn nearby. According to crime TV shows such as "Law and Order," who base episodes off of real events, most serial killers often like to leave a calling card or mark their "doings" so to say.

The faces continued to become more gruesome than the previous one but the most sinister one was found in Iowa that was drawn in red with devil's horn with a note reading, "Evil Happy Smily Face Man". The detectives then went on to find 12 other matching symbols linked to gang graffiti.

Not enough evidence has been found to link someone to the killer yet. I truly believe that the similarities between the men and most of their bodies being found near a body of water is not due to accidental drowning but from the work of a gang or serial killer.

Who knew what menacing and taunting smiley faces could become.