Crime in Chicago is bad. Everyone knows this. But for the most part it's pretty predictable crime — gangs, drugs, turf wars, petty squabbles.

One FBI agent, however, thinks something more sinister might be in play right now in Chi-town:

A man who had been missing nearly a week was pulled from the Chicago River Sunday, becoming the 16th person found in the Windy City's waterways in the past year and a half.

The disturbing pattern of people turning up in both the Chicago River and Lake Michigan have led a former FBI agent to suggest there may be a serial killer on the loose.

Now, to be fair, many of these deaths have been ruled as non-homicides, at least by the judgment of investigators:

Cops and detectives, of course, get these things wrong sometimes.

Former FBI Agent Tracy Wilder thinks there's too many coincidences to dismiss the serial killer theory out of hand:

'In a case like this, there are so many similar patterns right across the board [so] it's not just a coincidence anymore,' she added, citing how far the bodies have been recovered from where they were reported missing and the cases of 'accidental' drownings.

Serial killers were more prevalent in earlier decades, but advances in criminology and detection technology have whittled their numbers down, with Northeastern University noting that those tech developments "made it difficult for serial killers, let alone anyone involved in violent crime, to stay out of prison."

Chicago has led the nation in homicides for nearly a dozen years, recording over 600 killings last year alone.

The last year its homicides dropped beneath 400 was in 1965.