Crowd-sourced sleuthing on sites like Websleuths and Reddit has gained a new profile — and a whiff of respectability. (Illustration by The Washington Post)

Margaretta Evans has not seen nor heard from her son Jason in almost 20 years. One day in early June 1995, the then-18 year old told his mother he was leaving home to follow the Grateful Dead on their summer tour. Jason never came home.

Evans, now 63, didn’t know what happened to her son until she saw his picture in January on a Facebook page devoted to cold cases, organized by amateur Internet sleuths.

“OMG this is my son Jason Callahan from myrtle beach SC,” she wrote on the site for “Grateful Doe” — the name given to the unidentified victim of a car accident that killed two people in Virginia 20 years ago. “I’ve been looking for him for all this time with no luck. Today, my other son saw this FB page, and after all the years of praying for him to just call me or come home . . .”

Two decades missing — but thanks to the Internet, she may finally know.

‘‘They read Websleuths’

The Web has a history of amateur sleuthing stretching back almost as long as Evans’s vigil. Long before Reddit became infamous for the Boston bombing witch hunt, or the podcast “Serial” captivated millions with its investigation of a Baltimore murder case, thousands of keyboard detectives toiled in obscurity, ignored by the mainstream media and largely derided by police.

But more recently, crowdsourced sleuthing has gained a new profile — and a whiff of respectability. Legal scholars are probing whether Web forums and armchair detectives could better serve the legal system. In Britain, a leading forensic education group is drafting an online crime-solving program available to anyone. And police in several jurisdictions have started turning to the Internet masses to help find clues to crimes that would otherwise drift out of public view.

It is, at long last, the era of the Internet sleuth.

[‘Serial’: An investigative journalism podcast becomes a cultural obsession]

“Some law enforcement love us and want to take us to prom. Some of them hate us,” said Tricia Griffith, the owner of long-running crime forum Websleuths. “But I’ll tell you what — love us or hate us, I know they read Websleuths.”

Websleuths is, in many ways, a forerunner to today’s more sophisticated efforts. For Griffith, JonBenet Ramsey was the gateway case: In 1996, she read a news article on the child beauty queen’s murder and the many questions it raised. She has been running true-crime forums ever since.

Unless you spend a lot of time watching Nancy Grace or reading the tabloids, it’s hard to see much value in the speculation that often passes for detective work on Websleuths. Its registered members — who number roughly 75,000 — enjoy combing through the missing-persons database, hashing (and rehashing) criminal time lines and crowding their signature fields with the names of missing children: #justiceforhaley, #justiceforcaylee, #justiceforjennifer. But despite some 11 million posts in a quarter-million threads, Griffith struggles to come up with a time when they actually solved anything.

It would seem that Websleuths’ great talent lies in opening cases, not closing them. Sure, you’ll find gossipy housewives and homebound retirees, unchecked Nancy Drews convinced that they can out-police the police. But from the beginning, many of the Internet’s most devoted detectives have just wanted to keep cold cases alive, convinced that one more witness, one more detail, could somehow sift out with time.

“I have posted this everywhere,” wrote one Websleuths user in July 2005. “Please try to help me find this one.”

The title: VA - Grateful Dead Fan — Unidentified male, 26 June 1995.

Boston’s cautionary tale

Unidentified persons, incidentally, make good cases for Internet sleuths. Compared with, say, a murder or a bombing at a marathon finish line, they leave less room for the kind of finger-pointing and scandal that often make amateur detectives problematic.

In April 2013, after the Boston Marathon bombings, Reddit’s freewheeling armchair sleuths pored over photographs and surveillance footage and identified dozens of “suspicious” men in photos from the marathon finish line. One of the men that Reddit accused, a 22-year-old college student whose missing-person report caught their eye, turned out to have committed suicide, a tragedy unrelated to the bombing that compounded his family’s grief. Two other men singled out by Reddit— one of them only 16 — were plastered on the cover of the New York Post, wrongly branded as suspects.

[Backpack Brothers’ an example of the drawbacks to Internet sleuthing]

Talk to any self-identified sleuths today, and they’ll inevitably bring up the Boston bombing case. Often it’s with a grimace, as in: I swear, we learned from this.

The number of people interested in online crime-solving swelled after Boston. At its height, nearly 8,000 people subscribed to the “find Boston bombers” subreddit, or mini-community. It’s a number that pales in comparison to the current populations of Reddit’s investigative forums. The forum /r/SerialPodcast, which focuses on the Adnan Syed case at the center of the podcast, has grown to more than 40,000 subscribers since November, and /r/UnresolvedMysteries, which had just 200 users when it started in April 2014, is up to 80,000 today.

Asked at a panel in February whether she’d turn Syed’s case over to Reddit now that her podcast was over, Sarah Koenig, Serial’s host, said she wasn’t convinced it was “a good idea.”

“The one-thousand-foot, glaring red thing about crowdsourcing investigations is that it operates without the ethical rules or legal restraints that lawyers and law enforcement obey,” said Margaret Hagan, a lecturer at Stanford who studies ways to make the legal system more accessible to laypeople. “The crowd can be a powerful force for surfacing connections and details. But the mob effect terrifies me.”

Scouring for Grateful Doe

To call yourself a cyber sleuth, you have to first learn the basics. Familiarize yourself with cold-case and missing-persons Web sites, which usually host all the public records pertinent to your case. Next, pick up some advanced Google-stalking techniques, like how to find addresses from polling places and where to locate prior versions of since-altered Web pages. Finally: Click a thread, any thread. There are thousands of them.

In June 1995, a car carrying two young men crashed in Emporia, Va., leaving both dead. The 21-year-old driver was promptly identified by his family. But his passenger, a young man with longish dyed-red hair and a tie-dyed Grateful Dead T-shirt, carried nothing but a couple of scalped tickets to a Grateful Dead show at RFK Stadium.

The driver’s family didn’t recognize him. Nobody did. In fact, even after several years and several rounds of testing, “Grateful Doe” didn’t show up in any state or missing-persons databases — not even when police digitally reconstructed his image in 2012.

[When loved ones go missing, don’t count on technology to save them ]

By 2013 — eight years after the case had first appeared on Websleuths, and 18 years after Grateful Doe died — the site had proffered and ruled out 181 separate theories on who he could possibly be, mostly by cross-referencing his details with those in missing-persons databases.

Could he be James Cooper from Monroe, Mich.? (No; James had blue eyes and went missing in ’96.) Jack Jason Simmons? (Wrong hair color.) Phillip Koss? (No scar on his left upper arm, and no wire-frame glasses found at the scene.)

Members of the forum called the officer who worked Doe’s case to ask for information onscars, birthmarks or other identifying details. They attempted to call the phone number — lacking an area code — scrawled on a piece of paper in Doe’s pocket, signed “Caroline O. and Caroline T.” When no one picked up, they looked up women named Caroline in every city where numbers have the same 914 prefix. They interviewed people who had been at the Grateful Dead show in the District, or who had been to any show, or who merely liked them.

Yet as the 20th anniversary of Doe’s death grew nearer without leads, the sleuths decided they needed to try a new tactic. In mid-December of 2014, a community of longtime Doe watchers — led by an Australian woman using the alias “greymetal” — began an all-out social media offensive to gather new evidence on the case. The timing was no mistake: “Serial” had wrapped Dec. 18, leaving hordes of newly minted Internet sleuths with a lot of free time on their hands.

The Grateful Doe sleuths opened a Reddit forum dedicated to the case, which attracted 800 users; they posted Doe’s image to the popular image-sharing site Imgur, where almost half a million people viewed it. They circulated the image in jam-band and Grateful Dead forums, even finding a Rockville, Md., woman — Lauren Rutley — to serve as spokeswoman for the campaign. Rutley reached out to local media outlets and wrote a contributor post for Buzzfeed; she posted Doe’s picture wherever she could.

The text on the picture read: “Do you know me?”

Finally, someone replied: a man who had been Doe’s roommate for a few months in 1994. Then another who thought Doe had once stayed with his parents in Myrtle Beach.

“I’m just some low-level data person,” said Rutley, who had followed the case since she attended the University of Maryland in the mid-’90s. “All I did was share a picture. It just had to be seen at the right time, in the right place, by the right eyes.”

Energized by the new leads, users on several forums — including Reddit, Facebook and Websleuths — began blitzing South Carolina papers and TV networks with the story. They hoped to find some neighbor or classmate who had, for whatever reason, not spoken previously.

On Jan. 13, a long-awaited answer surfaced on the Grateful Doe Facebook page.

“OMG this is my son.”

The case backlog ahead

It’s not entirely clear why Margaretta Evans failed to report her 18-year-old son missing for so many years (local police have said that she didn’t know which jurisdiction to call because he’d been on the road with the Dead so long). It’s also still unconfirmed whether Grateful Doe is, in fact, Jason Callahan. Police are currently checking Doe’s DNA against the Evans family’s, and Evans has declined to elaborate until the results come back.

“I’m praying he’s still alive,” she said.

Whatever the results, advocates point out, there are still tens of thousands of Jasons out there, their cases lost to time or long-derelict forums. In 2013 alone, the National Center for Missing and Exploited Children logged more than 10,000 missing-children cases. Will there be #justiceforbabydoe? Or #justiceforshannalee? Can even the Internet crowd, in all its millions, address these numbers effectively?

That is the key challenge for the future, says Stanford’s Hagan. If crowdsleuthing is to evolve, advocates and investigators will have to find some responsible way to bridge their work with those of the Internet’s growing investigative community. To do that, they’ll have to first iron out the thorny ethical and procedural problems with crowd-based policing. “I can’t see lawyers going for it,” she says.

But Internet sleuths are not the type to wait around. On Reddit and Facebook, pages once dedicated to Grateful Doe have already converted to a new unidentified person’s case. “Fulton County Doe” also died inthe summer of 1995, apparently after leaving a Grateful Dead show. He had black hair, brown eyes and a tattoo that read “Virgo.”

Now, he’s another police sketch asking from a flat backlit screen: Do you — or you? or you? — know me?