"Green Light Killa:" Is Milwaukee man's death on railroad tracks the work of a serial killer?

MILWAUKEE -- Was it the work of the "Green Light Killa?" A person going by that name is claiming to be targeting men, and killing them on railroad tracks. Those claims made in another state are causing Milwaukee police to take a second look at a death that happened here.

A 51-year-old man died in September, and his death was originally ruled a suicide, but new clues from Tennessee indicate there might be more to this story.

Canadian Pacific tracks near Seeboth and S. Second Street

Jason Carroll died in September near Seeboth and S. Second Street. He was homeless, and the Milwaukee County Medical Examiner's Office says he died as a result of blunt force injury to his abdomen.

In October, the death was officially ruled a suicide -- but a postcard sent from Peoria, Illinois to the police department in Gallatin, Tennessee may change that.

Green Light Killa

The postcard is from a person going by the name: "Green Light Killa."

The postcard's author describes killing older, intoxicated men by placing them on railroad tracks. The "Green Light Killa" then watches from a distance, as a train hits the victims.

Gallatin police put out a bulletin to other police departments across the country -- and that bulletin caught to attention of the Milwaukee Police Department.

Green Light Killa and MPD investigation

Newly-unsealed documents show investigators say there are some similarities between the deaths described in the postcard and what happened to Jason Carroll.

Milwaukee police tell FOX6 News investigators tried to obtain surveillance video from the Canadian Pacific railway car that hit Carroll. The company allegedly denied MPD's request, and a subpoena was filed to obtain a copy.

Canadian Pacific tracks near Seeboth and S. Second Street

Police say the video will help investigators determine if this was an accidental death as originally thought, or a homicide.

Officials say no one has claimed responsibility for this incident, and FOX6 could't find any proof of a serial killer in Tennessee -- or Wisconsin.

FOX6 spoke with Carroll's mother by telephone. She said she was shocked to hear of this development.

She indicated she last spoke with MPD when her son's body was identified, and says he had a history of alcoholism and drug use. She says he had threatened suicide in the past.

No one was available from the Gallatin Police Department to talk with FOX6, and a representative from Canadian Pacific said this in a statement: