One of the first Somali-Americans from the Twin Cities to join a terrorist group overseas is a prominent online recruiter whose clout extends to a new wave of Minnesotans charged with conspiring to support extremists in the Middle East.

Mohamed Abdullahi Hassan's most recent display of influence came a week ago when he was linked by Twitter to the shooting at a Texas event where artists depicted their version of the prophet Mohammed. Before the shooting, Hassan sent messages urging his "brothers" to commit such an attack and later praised the gunmen who were killed.

His calls for violence from abroad highlighted the extent of his reach in the United States, which has been steadily growing since he left Minnesota in 2008. Hassan, known more commonly as "Miski," had already earned a reputation for his ability to stay ahead of federal authorities who want to silence him and others whose sophisticated use of social media is influencing new recruits to fight for the Islamic State of Iraq and the Levant (ISIL).

In the Twin Cities, Hassan represents the first link between the earlier waves of Somali youth who fled the U.S. for terrorism to a current group of young men charged last month for allegedly trying to do the same.

Hassan, who left as a 17-year-old student at Roosevelt High School in Minneapolis, was among the second wave of Somalis from the Twin Cities who first conspired in 2007 to fly to Somalia to join Al-Shabab.

From 2007 through 2013, at least 23 men from the metro area fled the U.S. in four separate waves, forcing the FBI to launch a counterterrorism investigation known as "Operation Rhino."

In 2009, Hassan was indicted by a federal grand jury for conspiracy to support terrorism. Today, he is one of nine Somali-American Minnesotans on an FBI most-wanted list of terrorists.

Now believed to be fighting in Somalia, Hassan was in close contact with Abdi Nur, a Somali-American who managed to fly out of the Twin Cities last May — a day after his friend, Abdullahi Yusef, was stopped by FBI agents from boarding a flight bound for Istanbul. Both men sought to continue on to Syria to join ISIL forces, according to charges.

Those two cases are part of a wider conspiracy under investigation and are tied to the recent arrests of six Somali-American men charged with plotting to leave the U.S. and fight for ISIL.

Roosevelt High links

Hassan's involvement in terrorism first came to light through the Operation Rhino investigation.

He was close friends with Ahmed Ali Omar, who left Minneapolis in 2007 as part of the first wave.

Omar's younger brother, Guled, is one of the six men arrested in late April and who himself tried to leave the U.S. three previous times, according to the FBI.

Sometime in 2007 or early 2008, the older Omar brother — nicknamed "Mustaf" — called Saynab Abdirashid Hussein, then a Minneapolis teen. Omar, who was calling from Somalia, told her to seek out his friend, "Miski," at Roosevelt High School, which they both attended.

When she did, Hassan described how invading Ethiopian troops were "raping women and killing children" in Somalia, according to documents that describe how she joined in the conspiracy.

Hassan asked for her help and introduced her to his sisters. Soon, the girls and other friends were soliciting donations to raise $1,300 for Hassan's plane ticket.

She also enlisted Hassan to act as a sort of "bag man" for other money to be sent over to support other fighters, according to her e-mails.

In one message to a fighter in Somalia, she wrote: "We'll have Miski send the money to yaa'l I just spoke with him now and hopefully he'll give you guys information. Please be patient with us were just trying to collect more and more money to send …"

Eventually, the Operation Rhino investigation uncovered her actions and in 2009, she was called before a federal grand jury.

There she lied about her knowledge of young men traveling to Somalia and denied raising money for Hassan and others. Agents also found she lied in 2012 when questioned again.

'I wish I could go back'

Last year, Chief District Judge Michael Davis sentenced Hussein, 24, to three years probation and community service. Remorseful, she told the judge, "I wish I could go back and change it all if I could."

Last August, when agents executed a search warrant to view Facebook messages between Nur and Hassan, they found a trove of conversational threads referring to Hassan's connections back to Minneapolis.

The messages showed a battle-hardened survivor trying to give advice to Nur, the newly arrived recruit who made it to Syria.

Nur told Hassan that he and two others had reached Syria, and others were still planning how to get there.

Hassan then told Nur: "Being connected in Jihad make you stronger and you can all help each other … the brothers from mpls are well connected so try to do the same. It is something we have learned after 6 years in Jihad."

Spurring on shooters

In addition to federal security agencies, analysts who track online extremist activity are closely monitoring Hassan, in part because of his ability to take the pulse of Somali communities across the U.S.

"He can empathize with any grievances, any feelings of persecution or feeling disaffected, and he can use those and exploit them," said David Ibsen, executive director of the Counter Extremism Project, based in New York.

Ibsen, who calls Hassan a "notorious cyber jihadi," says Hassan's influence was clear in the case of the shooting in Texas.

Before the shooting, Hassan and one of the shooters engaged in conversation over Twitter. "The brothers from the Charlie hebdo attack did their part. It's time for brothers in the #US to do their part," he tweeted April 23, referring to the attack on a satirical magazine in Paris earlier this year. He included a link with information about the Texas event.

Two days later, after the would-be shooter wrote about the treatment of Muslims by others, Hassan wrote back: "One individual is able to put a whole nation onto it's [sic] knees."

A week later, that man and a partner were killed by a police officer. The pair had shot and wounded a security guard at the event.

Hassan tweeted again, praising one of the shooters: "I'm going to miss his greeting every morning on Twitter."

Groups like the Counter Extremism Project have attempted to get Twitter to shut down the accounts of Hassan and others, with varying success.

Hassan has been more successful than others at re-emerging quickly.

ISIL supporters who lose their accounts often reappear quickly with the help of followers, according to the Jihad Terrorism Threat Monitor, a project of the Washington, D.C.-based Middle East Media Research Institute.

The group said if someone like Hassan reappears after getting shut down, others are quick to send out messages with his new Twitter account, which then is retweeted.

Now, the organization is putting pressure on Twitter to set up more checks and balances that could keep extremist thought out, or catch it more quickly.

Ibsen said Twitter has clear and fast responses for other types of objectionable posts, like those featuring child pornography.

He said Twitter should set up a system by which trusted monitors could flag posts and get removal requests moved up the chain more quickly.

For now, Hassan tweets on. In December, he bragged that he wouldn't be stopped, writing: "I got suspended 12 times but I'm still tweeting. Thats a proof I'm not giving up if you need a reason."

As of this week, Hassan has burned through more than 30 accounts.

Paul McEnroe • 612-673-1745

Erin Golden • 612-673-4790