An upcoming documentary will explore the chilling true story of a man who tortured and murdered his own mother before taking 277 photos (including selfies) of the gruesome crime scene.
Margaret Sumney, 67, was found dead in her bathtub at her home in South Fayette, Pennsylvania, in September 2019.
She had suffered broken ribs, a spinal fracture, cuts to her face and bruises all over her body when coroners ruled she ultimately died from blunt force trauma.
It was later determined that her then 30-year-old son David was responsible for her senseless death before he was sentenced to just 20 years behind bars – which many in the family felt was too lenient.
Here, FEMAIL has uncovered the harrowing details as an episode of American Monster prepares to present the case.
Margaret Sumney, 67, was found dead in her bathtub at her home in South Fayette, Pennsylvania, in September 2019, after being brutally murdered by son David (pictured together)
Sumney pleaded guilty to third-degree murder and was sentenced to a minimum of 20 years in prison after signing a plea agreement
The Max documentary will investigate how David Sumney Sr. and his wife Margaret ‘dedicated their lives to spoiling their only son’.
But it comes with a caveat: “Everything has a price, and when his parents divorce, David Jr.’s anger escalates, resulting in the deadliest of sins.”
Sumney, who grew up with two sisters, became increasingly violent and lashed out at those closest to him after his parents’ divorce.
In July 2015, he was charged with assaulting his father.
And in both August 2014 and November 2016, he was accused of assaulting his mother.
But according to his family, the charges in those cases were downgraded to assault and harassment.
Margaret described the attack on her in November 2016 in a handwritten note to police, previously obtained by DailyMail.com.
She wrote that “he tried to kill me,” “hit my face and body, strangled me, pulled my hand over my body,” and told her, “I’ll get you next time.”
In both August 2014 and November 2016, Sumney was accused of assaulting devoted mother Margaret
Margaret described the attack on her in November 2016 in a handwritten note to police, previously obtained by DailyMail.com
Curiously, she said her son was a Navy Seal, but a family member told DailyMail.com that investigators later discovered he lied about his military service.
Despite the violent outbursts, Sumney largely avoided jail time, in part because his mother urged leniency.
In July 2019, about two months before his mother’s death, Sumney’s ex-girlfriend alleged that he tortured her for three days at a hotel in Atlantic City, New Jersey.
She said she was strangled and waterboarded before being rescued by a bellhop who found her in the room after the couple failed to check out.
Local police quickly identified the suspect and obtained a warrant to arrest Sumney for attempted murder the same day, but never acted on it.
The victim, who did not want to be named, and Sumney’s family said he instead managed to slip through the cracks after authorities failed to submit the warrant to National Crime Information Center, which allegedly alerted out-of-state police to arrest him. .
Sumney was then able to leave New Jersey and fly to Denver before returning to his home state of Pennsylvania, they told DailyMail.com at the time.
There he would face another confrontation with police after being arrested a month later for assaulting a Lyft driver — but his outstanding warrant went unnoticed.
Officers issued a summons charging him with simple assault, intimidation and physical strike, but were unaware of the warrant issued by the neighboring state.
And it would be just days later that he brutally attacked his mother.
But Sumney largely avoided jail time for the earlier attacks, in part because his mother pushed for leniency
Police found Margaret’s beaten and dismembered body in a bathtub at her home (second from left) on September 2, 2019
On September 2, 2019, Margaret’s family had attempted to contact her to let her know her brother had died, but she did not respond, according to the complaint.
Youngest daughter Peggy called police that morning requesting a welfare check, informing them that Sumney was staying at the house and had a history of elder abuse.
When authorities gained access to the house, they found a gruesome scene.
Police found Margaret’s beaten body in a bathtub with blood splattered throughout the house, including on the ceiling.
The pathologist compared her injuries to those from a fatal car crash, with lacerations covering her body, including her face and scalp, and fractures to her ribs and spine that would have left her paralyzed from the waist down, according to the Pittsburgh Post . Gazette.
Sumney was interviewed and a search of his iPhone revealed that he had documented his mother’s murder.
He had taken 277 hundreds of photos with her body, including one memorial selfie of his own blood-stained face, footage of him showing a “thumbs up” sign and a video of him washing his mother’s mutilated corpse in the bathtub.
Prosecutors also said in 2020 that before leaving his mother’s body in the home, Sumney had sought “how long does it take for a body to start decomposing?” and ‘how long do you wait before disposing of a body?’ on the Web.
Margaret’s body was left in the bathtub with blood splattered throughout the house, including on the ceiling
According to the Daily Beast, he was formally arrested just days after his mother’s murder and found to be in possession of his mother’s bracelet, necklace, bank card and three checks.
He had also bought a hotel room in Philadelphia after the murder and gave a hotel manager a set of pearls, telling her they were “from a special lady to a special lady.”
Sumney was originally charged with murder, abuse of a corpse, robbery and theft by unlawful taking, but those charges were later dropped.
Had he been convicted of the more serious charges, he would have received a mandatory life sentence.
Instead, he pleaded guilty to third-degree murder and was sentenced to a minimum of 20 years in prison after signing a plea deal.
During the trial, a doctor testified that Sumney may have been in an improper mental state due to high doses of Adderall in his bloodstream.
In court he apologized for his actions, insisting: ‘I can’t believe I would let myself get into such a state where I could do something so bad, so terrible. I can’t believe what I did, that I killed my own mother…
“To my family, my sisters and my aunts, I know it is impossible to forgive me. I don’t forgive myself. I just want to let them know that I am truly sorry.”
But Margaret’s family were devastated by the ruling and said they feared Sumney would track them down if he was released.
“This is absolutely not justice for my mother and it certainly does not keep society safe,” the victim’s eldest daughter, Ellen, emphasized in a conversation with DailyMail.com.
“I don’t understand why Pennsylvania doesn’t consider him dangerous enough to want to convict him of first-degree murder.”
“To ever release him?” she continued. ‘I don’t even have words for it. I don’t think you can fix David. Someone taking pictures, taking selfies while killing someone. He’s a murderer. That’s all he is. And I think he would definitely kill again.”