DELEVAN — Acting Cattaraugus County Sheriff Timothy S. Whitcomb said Friday that investigators do not yet have enough “probable cause” to make an arrest in the slaying of an 80-year-old Delevan man.

A Meals on Wheels delivery person found Wilbur L. Norton dead Tuesday morning on the floor, next to a sofa, in his first-floor apartment in Delevan Terrace Apartments.

The door to the apartment was unlocked, according to sources close to the investigation.

After an autopsy in Erie County Medical Center, Norton’s death was ruled a homicide Wednesday.

Cattaraugus County Coroner Cleon W. Easton III, who also is a Franklinville funeral director, said the victim’s body had no marks or signs of trauma.

Whitcomb said investigators, who continue to question people, said they have now located several relatives of Norton, who had worked as a tree cutter. Some live in Texas and include several sons and a caregiver.

Whitcomb declined further discussion of the investigation, including the cause of death.