Cosmo DiNardo who confessed to killing four men now says he's killed before

The man who has confessed to killing four men in Pennsylvania now says that he is responsible for two other murders.

Philadelphia Police sources say that Cosmo DiNardo claims he was involved in at least two other killings when he was 15 years old.

Investigators say they are looking into whether the claims are legitimate.

DiNardo does have a history of mental illness and was once committed by his own family to a mental health facility.

DiNardo confessed that he along with his cousin Sean Kratz, shot the men and buried them in a 12-foot deep hole on his family's farm.

He says the men were killed after he lured them to the property with a marijuana deal.

DiNardo may avoid the death penalty because of his confession to the 4 murders.