Retired detectives give warning after serial killer fears grow in US state as 16th body found in bayou

Two former NYPD detectives have issued harrowing warnings following attempts by Houston Police to shut down speculation that a serial killer is on a rampage in the city.

The comments of retired sergeants Joseph Giacalone and Kevin Gannon were made this week in the wake of the 16th dead body this year to be pulled out of one of Houston's handful of bayous.

The remains of an adult man (yet to be identified) was recovered from White Oak Bayou Wednesday (8 Oct) following reports of a suspect drowning.

The man's body is the seventh within the last month to be recovered from Texan waters, following that of 20-year-old university student Jade McKissic and five unidentified others - men and women whose ages range between 20 and 60.

16 bodies have been recovered from Houston bayous this year (Brett Coomer/Houston Chronicle via Getty Images)

The incident also marks the 16th this year alone whereby a body as been pulled from one of the city's slow-moving stream.

Despite the staggering death toll, responding officers insisting the cause of in the latest case was likely not foul play, with Houston's mayor John Whitmire attempting to shut down speculation that a serial killer is behind the crimes.

"Enough of misinformation [and] wild speculation by either social media, elected officials, candidates, the media," Whitmire declared in a press conference last month. "We do not have any evidence that there is a serial killer loose in Houston, Texas."

Despite describing the numbers as 'alarming', the politician suggested the possibility that homelessness, alcohol use, or mental health issues could be behind each incident. Whitmire added: "I grew up in Houston. Unfortunately, drowning in our bayous is not a new phenomenon."

Houston's Police Chief, Noe Diaz also agreed with the mayor's assertions, adding: "There is no evidence, and I repeat no evidence, to suggest that any of these incidents are connected."

The city's mayor spoke out against serial killer speculation (Kirk Sides/Houston Chronicle via Getty Images)

As we say, however, two former members of New York Police Department have since spoken out against these claims, issuing a warning about the risk of ruling out a multiple-murderer at this stage.

Joseph Giacalone told Fox News: "Something is afoot. A coincidence? Unlikely."

He added that a more thorough, 'careful investigation' needs to be carried out on each case, telling the broadcaster this needs to include including 'the 48 hours prior to the discovery of their disappearance'.

In agreement with Giacalone's assertions, former sergeant Kevin Gannon also spoke to the US news outlet, telling reporters that detectives should also tread carefully in ruling out the possibility that the 16 'drownings' could connected to the 'Smiley Face Theory'.

For those unfamiliar with the latter, this hypothesis (previously rejected by the FBI) argues that the 45 young men found dead in Midwestern rivers and streams over the last 30 years did not die under accidential circumstances, and could have been the victims of a serial killer - or killers.

16 bodies have been found in the last year (Jill Karnicki/Houston Chronicle via Getty Images)

Gannon continued: "We’ve never seen drowning numbers like this before, especially with a drowning occurring every other day in the same location.

"This is an aberration and not the normal age of our 700-plus 'potential victims', but that doesn’t mean they couldn’t be involved in killing these older individuals also, as they feel like they are pretty invincible right now and can act with impunity due to the police response."