Authorities say Maxwell Marion Morton took the picture after killing high school junior Ryan Mangan, 16, on Wednesday in Mangan's home in the Pittsburgh suburb of Jeannette.
The Pittsburgh Tribune-Review said Saturday that according to a police affidavit Morton sent the selfie to a friend who turned it over his mother. She, in turn, gave it to police.
The affidavit also said that Morton sent the friend several messages including one that said, "Told you I cleaned up the shells," and another that said, "Ryan was not the last one," the newspaper reported.
"(Police) received a copy of the photo which depicted the victim sitting in the chair with a gunshot wound to the face," the newspaper quoted the affidavit as saying. "It also depicts a black male taking the ‘selfie' with his face facing the camera and the victim behind the actor."
The affidavit went on to say that across the top of the selfie was the name "Maxwell."
The Tribune-Review said the selfie showed Mangan as he was found dead at the scene.
Authorities said Morton confessed to shooting Mangan with a 9 mm handgun that was found in the basement of Morton's home.
Morton was being held without bail after his arraignment on a first degree murder charge and other charges. He is being charged as an adult.
Morton and Mangan were students in the Jeannette City School District, the newspaper said.A funeral fund has been set up for Mangan: http://www.gofundme.com/lkw4sg
Read more: http://www.foxnews.com/us/2015/02/07/pa-cops-say-teen-killed-another-teen-posed-with-body-for-selfie/