Cayman Naib, 13, vanished Wednesday after leaving his home in Newtown Township without his wallet or his phone, according to his parents.
A K-9 unit located his body Sunday afternoon some 150 yards away from his home, said Mark Hopkins, chief of Greater Philadelphia Search and Rescue. Hopkins said Naib was under snow, and in a "sleeping position."
Brian Razzi, chief of administration at the Delaware County Medical Examiner's Office, determined Monday that it was a suicide.
Naib's parents confirmed the news on Facebook.
"For those who have been following the Naib family's sad and incredibly devastating news, we have just learned from the medical examiner's office that Cayman took his own life," wrote Becky and Farid Naib. "The cause of death was a self-inflicted gunshot wound to his head."
They said the gun had been taken from the home.
"The police have informed us that despite being fitted with a trigger lock, the gun was still able to be fired," they said Monday.
The Naibs said Cayman's suicide most likely occurred Wednesday evening, just hours after he walked out of his home upon receiving an upsetting email from his school.
"Cayman left within 30 minutes after he received an email from school regarding overdue homework (we do not blame the school) and most probably did not do any preplanning," read a Thursday facebook post. "He is a good kid, and has no substance abuse or other issues, this is the first time he has ever done anything like this," the parents wrote.
A search for the teen had drawn hundreds of volunteers, who traded messages and posted updates on a Facebook page called "Find Cayman."
"The family would like to reiterate their profound gratitude and appreciation for all the thousands of friends, family, community, law enforcement, local, county, and federal, search and rescue, fire departments, the school communities ... and even perfect strangers who came out to volunteer, supported them with prayers and good wishes, and have loved them through this heartbreaking ordeal," read a Monday post on the site, since renamed "Celebrating Cayman." "Their only solace throughout these past few days has been the closure they have received from the community's efforts to find Cayman."