The first document showed 25 black and white photos of extraterrestrial life forms, the second reported suspicions by the US government of alleged alien interference with mankind.
Suddenly, in 1999, he expatriated his family from the United States, then locked himself in his home in Arizona, bought on a plot of land on which the US government had no jurisdiction; so they could not have come in to arrest him.
At that point he began to openly denounce the existence of a powerful group of conspirators called enlightened, who aimed to plunge the world into terror by pretending that there was an invasion by aliens based on spaceships, abductions of humans, mutilations, murders .
In reality it would have been military operations conducted by a particular secret service operating department.
Cooper denounced that the conspiracy had been used not only by accomplices, but also by secret agents completely unaware of the plot, making them believe that an alien invasion was really taking place; in reality it was terrestrial technology is of mutated clones, produced in the laboratory so that they seemed extraterrestrial life forms. Facing unknowing humanity with a bloody war against fake aliens, the Illuminati would have succeeded in uniting all nations under the aegis of only one government and one day they would build a new world order on the ruins of the old one. After issuing these statements suddenly William Milton Cooper was accused of tax evasion the former secret agent defended himself saying that they were all slander, the United States However they could not arrest him because of the lack of jurisdiction over his property, but the night of November 5 In 2001, the police pulled him out of the house, simulating nighttime noise.
According to the facts version of the Cooper authority he would have gone mad and fired first on them.
In self-defense, the police would have responded to the fire by killing him.

The true dynamic of what has happened has never been clarified, I leave your intuition to understand what really happened