Covered in his wife and children’s blood, he contacted 911 and told the operator a terrifying tale that his home had been stormed by Charles Manson-style hippies – saying they killed his wife and two daughters.
MacDonald – a tall, good-looking army surgeon – appeared to be the ideal family man and he at first managed to convince cops he was the victim. No one would have suspected that he could have been capable of such sick violence.
The All-American doctor thought he had committed the perfect murders and was going to get away with his crimes.
But after nine years he was eventually caught out as detectives and his father-in-law managed to unpick the twisted surgeon’s web of lies.
Despite his cool and professional demeanour, MacDonald gave himself away with several key clues.
The discovery of the murder weapons in the back garden of the house, with fingerprints mysteriously wiped off, pointed to a killer who hadn’t left the scene.
He also provided very little evidence to support his lurid claims of a marauding gang of murderous hippies, and refused to take a lie detector test.
Also, despite his training in unarmed combat, the room where MacDonald had supposedly fought for his life with his attackers showed few signs of struggle.
Fibres from his pyjama top were found beneath his wife’s body and in the bedrooms of his two daughters.
When police first arrived at the house in Fort Bragg, North Carolina, they were greeted with a sickening scene.
Cold and calculated, MacDonald himself had put the call in to police at 3.30 am on February 17, 1970.
When police arrived, they found him covered in blood lying next to his pregnant wife’s corpse.
Colette had been stabbed 16 times with a kitchen knife and 21 times with an icepick, and both of her arms were broken.
The couple’s oldest daughter, five-year-old Kimberley, had been bludgeoned to death and stabbed in the neck.
Little Kristen, two, had 48 separate stab wounds.
MacDonald, 26, a doctor and Green Beret, had suffered a punctured lung and several stab wounds, as well as a bruise to the head.
He had recently finished a 24-hour shift at the nearby Hamlet Hospital.
In the garden, investigators later found the murder weapons, an icepick and a large piece of wood.
MacDonald claimed to police that he had been asleep on the sofa when he was attacked by “a hippie gang”.
They included a woman in a hat who chanted “acid is groovy” and “kill the pigs”.
The word “pig” had been scrawled in blood on a headboard, in an apparent imitation of the Charles Manson killings a year earlier.
MacDonald said he had been knocked unconscious in the attack and, when he came to, his wife of six years and two young daughters were all dead.
Born in Long Island, New York, in school, Jeffrey was a popular child at school becoming student body president and prom king and was voted most popular and most likely to succeed by his classmates.
He met his wife Collette in 9th grade and they started dating, although later breaking up, but the high school sweethearts eventually got back together and, in 1963, the pair got married in a shotgun wedding after learning that Collette was pregnant.
A year later, their first child Kimberley was born.
After joining the army and later volunteering to become a Green Beret, the family eventually moved into a row house in Fort Bragg and Collette became pregnant a third time with the couple’s first son.
After MacDonald was treated for his injuries – which were far less severe than those the rest of his family suffered he was questioned by authorities.
Further investigations found that there was no evidence of MacDonald’s “hippy gang”, and several suspected weapons discovered around the property had been suspiciously wiped of fingerprints.
Forensic tests also came up with a number of findings and additional evidence that contradicted what MacDonald claimed had happened.
MacDonald himself also provided little evidence to support his claims and refused to take a lie detector test having earlier agreed to do so.
On May 1, 1970, he was charged with murder.
At his first trial, MacDonald’s attorney Bernard Segal alleged that forensic investigators had destroyed crucial evidence supporting his client’s story.
He even put forward a woman as a potential suspect – a teenage drug addict and police informant Helena Stoeckley.
She fit MacDonald’s description of a blonde woman he alleged had been at the scene of the murders and had been seen by a witness on the night the killings took place with several young men.
Stoeckley also couldn’t recall where she had been on the night of the crimes and had allegedly told a witness she couldn’t marry her boyfriend until they had killed someone.
Although both Stoeckley and her boyfriend were questioned about the murders, they were never brought to trial, and eventually, the charges against MacDonald were dropped in October 1970.
After he was discharged from the Army, MacDonald relocated to California to work as a doctor.
He became something of a celebrity, even appearing on TV for interviews.
However, Collette’s stepfather Alfred Kassab, who had originally supported MacDonald, had become increasingly suspicious of him.
He began his own investigation, acquired a transcript of MacDonald’s police interview, and even revisited the original crime scene.
Eventually, Kassab was convinced; MacDonald had murdered his stepdaughter and two children.
After a lengthy legal row, MacDonald was brought to trial for a second time on July 16, 1979.
On August 29, 1979, MacDonald was found guilty of one count of first-degree murder and two counts of second-degree murder and was handed three life sentences.
MacDonald had been so convinced that he would be found innocent that, before he was convicted, he invited author Joe McGinniss to write a book about the case that would exonerate him.
Instead, the book Fatal Invasion portrayed MacDonald as a cold, calculating killer with no remorse for his actions.
More than four decades have passed since his sentencing, but MacDonald has maintained his innocence to this day. He has filed several appeals but remains incarcerated at Cumberland Federal Correctional Institution in Maryland.
In August 2002, he even married his former children’s drama school owner Kathryn Kurichh.
In 1998, MacDonald professed his innocence again in an interview with Vanity Fair.
“I am a decent human being,” he claimed. “My guilt was over not being able to defend my family.
“They died. I didn’t… I didn’t have the luxury of choosing my assailants and telling them the foot-pounds per square inch they were to apply to my head and chest.”
He has his defenders. Campaigning filmmaker Errol Morris launched a bid to release MacDonald in 2012.
Speaking to CBS at the time, Morris said: “I believe him to be innocent because no one has ever shown me any kind of convincing argument for his guilt.”
He even wrote a book, A Wilderness of Error, which laid out all the evidence that he believes should free MacDonald.
However, last year The Fayetteville Observer reported that MacDonald had dropped his latest bid for freedom.
Federal records didn’t indicate why the 78-year-old cancelled his request to be released, and it isn’t known whether he has finally resigned himself to dying in prison.