UPDATE: Matthew Mindler's death by suicide by caused by complications of sodium nitrate toxicity, according to the Lancaster County Coroner's report, which E! News obtained on Thursday, Oct. 14.
Sodium nitrate is an oxidizing agent often used to preserve food. TMZ reported that the actor acquired the substance online and quoted his mother, Monica Mindler, as saying her son had recently researched the compound on the internet as it pertains to painless suicide.
Matthew Mindler's untimely death has been ruled a suicide.
On Aug. 30, two days after the former child actor's remains were recovered near his Pennsylvania college campus, the Lancaster County Coroner's Office told NBC News he died by suicide. The exact cause of Mindler's passing is pending toxicology results, officials said.
Mindler was first reported missing by his family on Aug. 25 after he failed to attend class or return to his Millersville University dorm room after being spotted on security footage the night before. At approximately 8 p.m. on Aug. 24, the 19-year-old student was seen exiting his residence building carrying a backpack and wearing black pants and a Millersville University sweatshirt.
Millersville University President Daniel A. Wubah confirmed news of Miller's death in a letter addressed to staff and students and shared to social media.
Wubah indicated that Miller was found deceased in Manor Township, Penn., which is located approximately five miles from campus.
"This is a time of grief for the family, our campus and the community," the statement read. "I ask that the campus community come together to support each other, and our students, during this difficult time."
Mindler was thrust into the spotlight opposite Paul Rudd in the 2011 film Our Idiot Brother. The late star's other credited roles included As the World Turns, as well as short films and TV movies.
His mother, Monica Mindler, told The Morning Call that at the time of his disappearance he had not acted professionally in several years. She has not commented publicly on his death.
(This story was originally published on Aug. 31, 2021 at 8:12 a.m. PT)