Sean Penn reveals chilling thought after finding himself alone with the 'Night Stalker' in jail

Sean Penn admits he briefly considered attacking one of America's most infamous serial killers after the two unexpectedly came face to face behind bars.

In a recent interview with VICE News, the actor recalled spending 34 days in Los Angeles County Jail during the height of his early Hollywood success. Penn said he was in his mid-20s, had already starred in "Taps" and filmed "Colors," and was married to Madonna when he crossed paths with the "Night Stalker."

"I got moved out of general population because of some kind of threat," the 65-year-old told the outlet. "... And a lot of guys on this department ... they invest a lot in pretending not to give a s--- about Hollywood culture, but they sure do like to gossip [about] what they see."

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"So, I slept with one eye open, of course," he said. "... Then I got moved to [an] eight and a half by 11 by myself for most of the time. And through a little wire glass door, there's Richard Ramirez, not 20 feet away. And we're both insomniacs."

Shackled and belly chained for a phone call, the actor said he was escorted into an otherwise empty room — only to discover Ramirez sitting beside him.

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"I came out of my cell for a phone call," Penn told the outlet. "So they take you shackled and belly chained, and they take one cuff off, put it on the eye hook so that you've got a hand for the phone. And Ramirez is seated right next to me. He's going to [make] a call also."

"There's nobody else there," said Penn. "There's nobody in there because somebody was throwing feces at somebody. It was a crazy kind of thing happening. And I did have that question. I knew what he did to some of these people. This wasn't today's phones or your cell phone, right?"

"I'm right next to him," said Penn. "I could, I could ..."

"Flatten him out," said the host.

The Oscar winner admitted he thought better of it despite having access to him "twice."

"But who was I?" said Penn. "It was just another person. And I'm so glad I didn't think I was important enough to do that, but you have the thought."

Ramirez was convicted of 13 murders during a killing spree that gripped Southern California in 1984 and 1985.

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His reign of terror peaked in the summer of 1985, when he slipped into homes through unlocked doors and windows before murdering victims, sexually assaulting women and burglarizing homes. He also left satanic symbols at several crime scenes.

The press dubbed him the "Night Stalker" as authorities warned Southern California residents to lock their doors and windows after dark.

Ramirez's slayings ended in 1985 after residents of an East Los Angeles neighborhood recognized him from news reports, chased him down and beat him before police took him into custody following a failed carjacking.

During his trial, the Texas native attracted a following of young women who regularly attended court proceedings and sent him love letters.

Ramirez died in 2013 at age 53 from cancer while awaiting execution on California's death row at San Quentin State Prison.

Years before, Penn revealed another bizarre detail about their time behind bars: The serial killer wanted his autograph. Speaking to The Hollywood Reporter in 2015, Penn said Ramirez sent word through a deputy requesting a signed keepsake.

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"He wrote me [a letter]," said Penn. "I was down here on Bauchet Street, in LA County Jail, in the cell kind of across from him. And after a month of seeing each other around, he wanted my autograph. So, he sent one of the deputies over, [and the] deputy came to my cell and told me, ‘Hey, Richard Ramirez wants your autograph.’ And I didn’t trust the deputy because I’d gotten in some trouble inside there and just passing a piece of paper is contraband, so you can get extra days for that, and I already had extra days and I didn’t want more."

"So, I said, ‘Bring the sergeant down here, and I’ll talk to him, and if he approves it, then I want him to write something first, and I’ll write him something back,’" said Penn. "So, the sergeant came down and approved it, and they went over to Ramirez — this guard basically wanted to play cupid, in some way. So, I get this thing from him, and it says, ‘Hey Sean, stay tough and hit them again — Richard Ramirez, 666,’ with a pentagram and a rendition of the devil."

Penn wrote back.

"I said, ‘You know, Richard, it’s impossible to be incarcerated and not feel a certain kinship with your fellow inmates. Well, Richard, I’ve done the impossible. I feel absolutely no kinship with you. And I hope gas descends upon you before sanity does, you know? It would be a kinder way out.’"

"And they gave it to him," said Penn. "And then my house burned down years later, and that damn thing of his burned with it."