Texas police have found at least 16 bodies in the bayous around Houston so far this year, according to authorities and local reports, sparking concerns of a serial killer which city leaders are working to dispel.

Houston’s mayor has said police have no evidence of a serial killer, but experts are calling for an extensive investigation into the deaths.

“Something is afoot,” said Joseph Giacalone, a retired NYPD sergeant and criminal justice professor, at Penn State-Lehigh Valley. “A coincidence? Unlikely. A careful inspection of each case is warranted, including the 48 hours prior to the discovery of their disappearance.”

The spate of apparent drownings is reminiscent of another concerning number of deaths in the waters of Lady Bird Lake in Austin, Texas.

Whitmire suggested that when homeless people die, their friends often throw them in the water.

“Unfortunately the homeless, when they pass, often end up in the bayou,” he said.

He also pointed to alcohol use and mental health problems as potential factors in the deaths.