On November 18, 1978, the Reverend Jim Jones ordered his followers to carry out a "revolutionary suicide" at their compound in the jungles of Guyana, a former British colony in the Caribbean.
Anne had been Jim Jones' nurse and Carolyn had been his lover and both were key to the leadership of the People's Temple, the "apostolic socialist" group which Jones set up in the US and then brought to Guyana.
Mr. McGehee said many conspiracy theories had sprung up since the bodies were discovered by Guyanese soldiers the following morning.
Conspiracy Theorists Blamed Everyone From CIA to Guyanese President
"To date we have heard of about 20 different conspiracy theories ranging from CIA mind control to Jim Jones being a rogue CIA agent who had to be taken out or he was a conscientious CIA agent who was about to blow the whistle on himself, or (Guyanese President) Forbes Burnham did it because his ministers were involved in a sex and drugs scandal in Jonestown, to it being caused by a neutron bomb or AIDS," Mr. McGehee told Sputnik.
"My wife and I tend to reject the idea of CIA mind control. After 40 years someone within the conspiracy would have broken the silence, either with a deathbed confession or a book deal. To ask that many people to stay silent for 40 years beggars credulity," Mr. McGehee told Sputnik.
"What it comes down to is that here are all these parents that killed their children before killing themselves. No-one does that. That's impossible. So what's next? But that is what happened. The reality was just too horrible for people to accept," Mr. McGehee told Sputnik.
Jones, who was born in Indiana and flirted with communism as a young man, formed the People's Temple and recruited followers, many of them African-American, before relocating to California.
But he grew tired of the restrictions of life in the United States and persuaded his followers to move to an isolated compound in Guyana, which was quickly dubbed Jonestown.
Area of Guyana Was Coveted by Venezuela
Mr. McGehee said the plot of land was gifted by the government of President Burnham because the north west of Guyana was the subject of a border dispute with neighbouring Venezuela and he felt the presence of the Americans could be useful if the Venezuelans ever invaded.
Defectors from the People's Temple contacted a US Congressman, Leo Ryan, and claimed people on the compound were being mistreated by Jones and the other leaders.
Ryan flew down on a fact-finding visit but it went badly wrong and he was gunned down at a nearby airstrip at Port Kaituma as he tried to get away.
It was then that Jones ordered his followers to kill their children — around 260 died at Jonestown — and then themselves.
The authorities eventually discovered 918 bodies and found a horrific audio recording of their last moments, in which Jones told the children not to cry as they take the "potion"."I'm tired of it all…we need to step across…can some people assure these children that they will be stepping over onto the next plane. We don't like the way the world is…this is a revolutionary suicide protesting at the conditions of an inhumane world," Jones can be heard to say on the tape.
On the tape one of his followers ask him if it they can all defect to the Soviet Union, but Jones tells them it is "too late".
"Do you think Russia is going to want us, with us all this stigma?" Jones tells her.
Terrible Timing of Congressman's Visit
Mr. McGehee said the timing of Congressman Ryan's visit was extremely unfortunate and proved fatal.
"Ryan arrived at the exact wrong moment. It was really bad timing. Jim Jones was physically ill and there was a good chance that he would have died or been incapacitate by the end of the year and there would have been a new leadership of the temple," Mr. McGehee told Sputnik.
He said when Ryan was killed Jones knew he would be arrested by the Guyanese authorities and Mr. McGehee said there were similarities with selfish and suicidal fathers who kill their children, except that Jones saw all his Jonestown followers as his children.
Mr. McGehee said he also thought Congressman Ryan did not expect to be allowed into the compound.
"I think he didn't expect to be allowed in. He thought he would stand in front, with a film crew, and be turned away. It would have been a photo opportunity and he would get political kudos from it. He was surprised when they let him in," Mr. McGehee told Sputnik.
'Don't Drink the Kool-Aid!'
For years the myth persisted that those who died drank Kool-Aid laced with potassium cyanide.
It was in fact a home-made punch but the phrase "Don't drink the Kool-Aid" — meaning do not give into peer pressure — seeped into US pop culture and can still be found on social media today.
Conspiracy theorists have made much of the fact that autopsies were only performed on a handful of the bodies and cyanide was not found but Mr. McGehee said that was because the bodies had been embalmed and organs which might have retained traces of the poison had been removed.
Of those who died only Jones and Anne Moore suffered gunshot wounds, believed to have been self-inflicted.
Mr. McGehee said he referred to the People's Temple as a "church" and not a "cult" and he also disliked the term "brainwashed".
"There was a lot of dissent within Jonestown. We will be at a meeting on Saturday (November 17) in the Bay area of around 50 survivors and there is not a lot they agree on. People knew the difference between right and wrong…but there was a lot of coercion and conditioning," Mr. McGehee told Sputnik.
The survivors were mainly those who had defected or those who were working for the charity in the Guyanese capital, Georgetown, or were with the temple's basketball team, which was at a tournament in the city when the massacre happened.
On Sunday, November 18, survivors and relatives of the dead will be meeting at the Jonestown Memorial, which is in a cemetery in Oakland, California.
How Did Seven People Survive Massacre?
Mr. McGehee said only seven people who were in the compound on the day survived.
"Three were young white men tasked by the leadership with taking a suitcase of money to the Soviet embassy, two were young black men who saw what was going on and said to themselves ‘no way', made an excuse and escaped, and one was an elderly black man who hid in a ditch for about eight hours," Mr. McGehee told Sputnik.
But the most amazing survivor's story is that of 73-year-old Hyacinth Thrash, who was originally from Indianapolis and followed Jones to Guyana after crediting him for curing her of breast cancer.
Don't drink the kool-aid pic.twitter.com/HST6lghbhr— televisionnutritiva (@telenutritiva) 15 November 2018
She slept through the whole massacre and awoke to find everybody dead.
"I remember those babies marching past our place with little paper hats on, wearing sandals, sun suits and matching shorts and tops. It's enough to make you scream your lungs out, thinking of those babies dead," she told the Indianapolis Star newspaper many years later.
"I just don't feel nothing towards him now, no bitterness towards him. I was at times, but I prayed to the Lord, because you can't hate nobody. So I was healed of that," Ms. Thrash added.
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