A baby boy was found dead, wrapped in a plastic bag in a Northwest Side gangway this weekend. About 8:30 a.m., the boy — described as a newborn — was found in a gangway in the 2700 block of North Hamlin Avenue, according to police and the Cook County medical examiner’s office. He was pronounced dead at the scene.

A police source described the baby as a “full-term male infant” who was 1 day old.

On Sunday, authorities hadn’t located the baby’s family or otherwise identified him. And an autopsy performed Sunday was inconclusive. More studies are underway to determine how the newborn died, according to the medical examiner’s office.

Detectives would not comment on the investigation.