For six months, he would have been ghosts: The Venezuelan would have buzzed Caracas in stolen helicopter, stolen from government weapons, released blistering statements against the Maduro regime on social media, and given interviews to journalists before melting away again.
In January 2018, a small army of Venezuelan security forces caught up to them, surrounding the group in the outskirts of Caracas. Perez posted videos of himself in the middle of the firefight; within hours, he would be dead.
His death kicked off a new dispute that has lasted to this day: Did Perez die fighting? The former police officer was too dangerous to live?
Before he died at age 36, he was a well-respected police instructor, skilled helicopter pilot and actor in a Venezuelan action film, but was not known outside law enforcement circles.
That changed on June 2017, when Perez stole a police helicopter and dropped stacks over the Supreme Court and Ministry of Interior in the heart of Caracas. He also released a video of the tyranny of Venezuela's socialist government.
He said, calling on the Venezuelan military to rise up and overthrow the ruling socialist "We are carrying out deployments by air and land to return to the democratic power government.
"Venezuela, we shall fight for liberty," Perez declared.
The South American nation's embattled president Nicolas Maduro described Perez and his supporters as terrorists and vowed to hunt them down.
That Perez had as out of seemingly nowhere and had done with the police made many Venezuelans wonder if his call to revolution was for real.
Many thought it was strange that Venezuelan security forces never attempted to shoot down Perez as he circled Caracas in the stolen helicopter, despite reports that Maduro's government had thousands of Russian surface-to-air missiles.
Adding to their suspicion was the fact that Venezuela's formidable intelligence services are known to be able to track down government opponents in hiding-seemed unable to find.
But when it came to the end in January 2018, when 500 military, police and paramilitary troops descended on the hilly parish of the Junquito and the small country house where he was hiding out.
Operation Gedeon, or "La Masacre de El Junquito"
Initially Perez seemed to think he could struck to save his men's lives, his social media postings suggest. Video posted on Instagram by Perez showed him talking calmly out of the window to an official and referred to as "major," trying to arrange a surrender.
Soon though a firefight broke out with the government forces bombarding the house with machine gun fire and rocket-propelled grenades.
The Maduro government says that Perez's men opened fire, killing two police officers and critically wounded six others. Opposition members said members of colectivos, pro-government paramilitary units, were felt to make sure Perez didn't leave the house alive.
A leader of a colectivo was also killed in the battle, Venezuelan opposition media reported. There is no record of this in the official death toll.
In the last video he posted, with blood down his face, Perez said the government refused to take him alive. "We are not shooting but they keep attacking," Perez said. "We are negotiating to turn ourselves over because there are innocent people here, there are civilians but they don't want us to."
The shootout raged for hours until the house where Perez and his supporters sought refuge was barely standing. Perez, five men and one woman who had been inside the house were killed.
The Venezuelan government called the action Operation Gedeon but the battle became known by another name, La Masacre de El Junquito, the Junquito massacre.
The Venezuelan government said Perez had been planning terror attacks when they found him, and he supported his fight to death. "He who would take the road of terrorism and takes arms against the republic, against the people," Maduro said in a nationally televised speech after the nine-hour siege ended. "Will be given a timely response from our armed forces and police. They shouldn't doubt it!"
Now, as relations between the US and Venezuela fray, Perez has been lionized by those trying to force Maduro from power.
"Oscar gave his life for the freedom of his people."
A leaked cache of secret photos?
Immediately following Perez's death, rumors began to circulate that had been captured alive, and had been executed by government forces.
In March, Venezuela's former Attorney General Luisa Ortega, who has lived in exile in Colombia since breaking with Maduro, said she had obtained proof that Perez had been captured alive and executed.
"Fortunately, some men are women who are inside the police forces and have agreed that they will have helped us to cooperate with the investigation," Ortega said.
Reaction over Ortega's accusations has been split down political lines. Government supporters say that Perez was a terrorist who deserved to die, no matter the circumstances. Members of Venezuela 's opposition, many of whom initially distanced themselves from Perez for using violence, have since embraced him as martyr.
In January, Juan Guaido, the National Assembly president who has been recognized as Venezuela's "Interim President" by more than 50 nations, called for a minute of silence in the National Assembly.
The Venezuelan government did not respond to CNN's request for comment about whether Perez and his supporters were executed.
"They weren't armed," Ortega told CNN in an interview. "This is proven by the bullet wounds, defensive wounds in the palm of their hands and their sides and their impact on their bodies."
Ballistic experts consulted by CNN were unable to confirm Ortega's claim based on the photos she tweeted. Peter Diaczuk and Angelique Corthals of the John Jay College of Criminal Justice in New York said.
Perez's supporters and the government forces. Ortega told CNN she is preparing to send the entire cache of photos and documents to the International Criminal Court in the Hague, to investigate the deaths as possibly extrajudicial killings.
While the ICC has not commented publicly on Perez's death or Ortega's accusations, the court is carrying out investigations into alleged human rights abuses by the Venezuelan government.