Northampton County Coroner Zachary Lysek said a toxicology test confirmed the presence of heroin in Garrett Reid's body. Investigators revealed they found a used syringe and spoon in his room, along with a gym bag filled with dozens of syringes and needles, many of them unopened.
"We are confident today that Mr. Reid's death was the result of a self-injected lethal dose of heroin," District Attorney John Morganelli said at a news conference in Easton.
Reid was found dead in his dorm room early on Aug. 5 at Lehigh University in Bethlehem, where he was assisting the team's strength and conditioning coach during training camp.
He was a recovering drug addict who had seemingly turned his life around. His father, Andy Reid, had indicated that his 29-year-old son may have had a relapse.
In a statement released through the Eagles, the Reid family said Garrett Reid's smile, laugh and energy will be missed.
"These results sadly confirmed what we had expected all along," the family's statement said. "We understood that Garrett's long-standing battle with addiction was going to be difficult. He will, however, always have our family's love and respect for the courage he showed in trying to overcome it. In the end, we take comfort in our faith and know that he's in a better place."
Lehigh University police were called to Garrett Reid's dorm room around 7:20 a.m., arriving after Eagles team physician Dr. Omar Elkhamra had tried to revive him with a defibrillator.
Investigators found 47 syringes and 65 needles in Reid's gym bag, along with 19 vials of an unknown liquid that Morganelli said will undergo testing.
"We're not sure, exactly, what those substances are at this time," he said, adding they had nothing to do with Garrett Reid's death.
Morganelli said the investigation is now focused on learning the identity of Garrett Reid's supplier. Investigators are combing through Reid's phone records to see who he was calling and texting in the days, weeks and months leading up to his death. Reid's body showed signs of chronic drug use, according to Lysek.
Reid seemed to have rebounded from a long struggle with drug abuse.
He was sentenced to nearly two years in prison for a 2007 high-speed car crash that injured another driver. Police said Reid was high on heroin, and they found the drug and more than 200 pills in his car.
"I don't want to die doing drugs. I don't want to be that kid who was the son of the head coach of the Eagles, who was spoiled and on drugs and OD'd and just faded into oblivion," he told the judge at his sentencing hearing.
More recently, exercise and training had become his passion and he aspired to make it a career. At the time of his death, he had been helping strength and conditioning coach Barry Rubin.
While Northampton County officials made it official on Thursday, Andy Reid had hinted at the cause of Garrett's death in a statement released shortly after his son's death. He said Garrett Reid had "lost the battle that has been ongoing for the last eight years."
Reid's younger brother, Britt, has also struggled with drug use and was arrested on the same day as Garrett in 2007 after a road-rage incident. Police discovered weapons and drugs in Britt Reid's vehicle. He now works as a graduate assistant coach at Temple.
The Reid family also sent encouragement to other families dealing with addiction.
"There are many other individuals and families engaged in this struggle in their own lives, and they will always have our support, encouragement, and understanding," the family said. "Never give up!"