A 13-foot alligator was spotted with human remains in its mouth in a canal in unincorporated Largo, Florida.

Jamarcus Bullard said he saw the alligator and a body in the water on 134th Avenue North on Friday afternoon.

“I threw a rock at the gator just to see if it was really a gator and like it pulled the body, like it was holding on to the lower part of the torso, and pulled it under the water,” he told NBC affiliate WFLA of Tampa.

Stunned, Bullard said he started recording on his cell phone and contacted authorities. A video he shared with the news station showed an officer with the Florida Fish and Wildlife Conservation Commission measuring the massive animal.

The 13-foot, 8.5-inch male alligator was removed from the water and was “humanely killed,” the Pinellas County Sheriff’s Office said in a news release. The remains of an adult were also recovered.

Authorities have not released details about the victim and an investigation remains ongoing. The medical examiner’s office will conduct an autopsy to determine the cause and manner of death.

The discovery has left some neighbors on edge.

Jennifer Dean told WFLA that her children frequently walk by the canal.

“So it’s really scary,” she said.

Bullard said he walks by the waterway to and from work and will be more vigilant now.

This article was originally published on NBCNews.com