The man holding “This is a sign!” stands behind Paul Manafort's lawyer Kevin Downing as he speaks with reporters after Manafort's sentencing Wednesday. (Marvin Joseph/The Washington Post)

He was already there when the professional photographers arrived early Wednesday to set up their stakeout outside the federal courthouse in Washington. He was there for the next six hours, leaning against the wall, inscrutably conspicuous in his purple fuzzy hat, purple bow tie and purple sunglasses.

And then, when lawyers for former Trump campaign chairman Paul Manafort finally emerged from his sentencing hearing to address the cameras, there he was directly behind them, photo-bombing another high-profile media circus with a sign that read, simply, “This is a sign!”

This-is-a-sign guy has become a fixture at camera scrums in and around the nation’s capital in recent months. By Thursday, he was haunting Roger Stone’s latest appearance at the same courthouse. He had been prominently in the frame at another Manafort’s sentencing this month in Alexandria. There they were, he and his sign, outside a Valentine’s Day appearance of former Starbucks’s CEO Howard Schultz.

But aside from his clockwork appearances in front of media scrums, it’s hard to find any sign of This-is-a-sign guy. He has a Twitter account (@ThisIsASignGuy) and a business card (which includes no information beyond his Twitter handle). While he has chatted briefly with reporters, photographers and other protesters, he hasn’t made his intentions clear to any.

“This is a sign!” Is the message meaningful? Or merely meta?

His Twitter bio says only: “I’m just a messenger.” His feed, going back to the end of January, is a string of retweets of other people’s picture of him holding his sign. Every now and then, he responds with a terse comment but little that gives a glimpse of the man behind the sign.

But until Wednesday night, pinned at the very top of his Twitter feed, was this verse in fractured meter:

“I saw a sign, from God, I think, just when I needed most; an answered prayer, a divining rod, a paranormal guidepost.”

Is he a religious messenger? This is a sign … of the apocalypse? The man’s color scheme recently shifted from orange head wear to purple, making him a potential observer of Lent. Or maybe Mardi Gras.

There is a publicity-stunt tradition of bewigged Christian zealots, most notably Rollen Stewart, who planted himself in many a sports broadcast in his rainbow Afro and “John 3:16” shirt (and who is now in prison for hostage taking).

After this story published Wednesday, This-is-a-sign guy responded to a request to expand on his four-word manifesto with a friendly no thanks: “Hope you are well. I will keep u in mind if/when I’d like to talk about the sign.”

Nothing more.

Trailed by This-is-a-sign guy, former Trump adviser Roger Stone (C), arrives for a court hearing on March 14, 2019, in Washington DC. (Andrew CABALLERO-REYNOLDS / AFP)ANDREW CABALLERO-REYNOLDS/AFP/Getty Images

“I don’t know what he’s up to,” said Bill Christeson, 64, another regular sign carrier who was seen stalking Manafort after one court appearance with a large “Traitor” placard. He described his scant exchanges with sign guy as friendly, brief and unrevealing.

Christeson himself is a lifelong human rights and anti-violence activist who has had his eye on Manafort’s career since the political consultant worked for Filipino strongman Ferdinand Marcos in the 1980s. At Wednesday’s sentencing, he held a sign that read “Blameless? Manafort Sold His Soul to Dictators.”

“I have a different sign at every one,” Christeson said. “I’m trying to brand these people as what I think they are.”

Christeson’s best guess about his cryptic color-rich colleague is that he’s up to no good. “He might be there to belittle the rest of us. It’s not hard for me to believe that someone’s paying him to make us all look crazy.”

A handful of protesters, and the This-is-a-sign guy, wait Wednesday as Paul Manafort is sentenced to 73 months in prison at U.S. District Court in Washington. (Marvin Joseph/The Washington Post)

But his interaction with the man Wednesday was innocent. They stood together, got their sliver of the media spotlight and headed off. Christeson boarded a train at the Judiciary Square Metro station, and after one stop, another rider approached him. It was This-is-a-sign guy, without the wig or sunglasses.

The man only wanted to give him a business card, and then he left.

“He looked like any other businessman,” Christeson said.

He looked average. Is that a sign?