This case was featured on Monday night’s People Magazine Investigates. Now go deeper with PEOPLE’s complete digital coverage.
For the past 47 years, former Green Beret surgeon Jeffrey MacDonald‘s account of what happened the night his entire family was murdered has remained the same.
MacDonald has said four intruders killed his wife, Colette, 26, and daughters Kimberley, 5, and Kristen, 2, at their Fort Bragg, North Carolina, home on Feb. 17, 1970. One of the intruders, he has said, was a woman with long blonde hair, wearing a floppy hat, holding what appeared to be a candle and chanting, “Acid is groovy. Kill the pigs.”
When military police arrived at their home, MacDonald was lying next to his wife in their bedroom; he says he’d been trying in vain to resuscitate her and their two daughters. He was unconscious, with head injuries, several stab wounds and a partially collapsed lung.
But three months later, the Army charged MacDonald with three counts of murder. Though ultimately cleared after a six-week hearing, MacDonald was charged again in 1975, this time by federal prosecutors. In August 1979, a jury found him guilty and he was sentenced to three consecutive life terms.
WATCH: Exclusive clip from People Magazine Investigates: ‘The Accused’
MacDonald’s case was the focus of the People Magazine Investigates season finale, “The Accused,” which aired Monday night on Investigation Discovery.
To this day, debate still rages over MacDonald’s guilt. On Jan. 26, the Fourth Circuit Court of Appeals will hear oral arguments on MacDonald’s claims of innocence.
• Watch the full episode of People Magazine Investigates After Show, streaming now on People/Entertainment Weekly Network (PEN). Go to PEOPLE.com/PEN, or download the app for Apple TV, Roku, Amazon Fire TV, Xumo, Chromecast, Xfinity, iOS and Android devices.
Over the past 37 years, MacDonald and his defense team have accumulated what they hope is enough evidence to exonerate him. Some of it is from the government’s own files and obtained via Freedom of Information Act requests, but none of it was heard by the jury that convicted him. A website started in 2000 by his second wife, Kathryn MacDonald, yielded some of the new witnesses for the appeal.
The newly discovered evidence includes: DNA tests on hairs found beneath one of Kristen’s fingernails, on her bedspread and beneath his wife; blonde wig hairs, 22 and 24 inches long, which the defense believes might match the female intruder MacDonald described; candle wax; black wool fibers found on one of the murder weapons, Colette’s biceps and her mouth that don’t match anything in the home — and multiple alleged confessions from two different suspects.
Both Helena Stoeckley and Greg Mitchell, who were boyfriend and girlfriend at the time, confessed their involvement to multiple people up until their deaths in the early 1980s.
U.S. Attorney John Bruce declined to comment on the specifics of the case, saying in a statement to PEOPLE: “When cases are pending court proceedings, it is the practice of our office to litigate the case in court — through evidence and argument in hearings and in written filings with the court — rather than through the news media.”