LOWELL -- When Nicola Benyahia's son, Rasheed, began acting differently in 2014, she did not think anything was amiss.
She thought it was understandable for him to want to drop out of college and pursue what he said was the more practical option of an engineering apprenticeship. She believed him when he explained that he had a second cell phone because his first phone did not work well. She thought, in his long sessions online, he was browsing social media or playing games.
When he did not come home one day in May 2015, Benyahia panicked, thinking he had been mugged or gotten into trouble. Then a message arrived from him a few days later, indicating he would not have a phone for 30 days and that his mother should not go to the police or media.
He had traveled from their home in Birmingham, England to join ISIS, drawn in after being radicalized online. Within a year, he was dead, reportedly killed by a drone strike near the border of Iraq and Syria.
Benyahia now travels around the world, speaking about her experience as part of the Families for Life organization she helped found to raise awareness about extremism on the internet. She was the keynote speaker at a UMass Lowell conference Friday about online recruitment by extremist groups.
"I knew the most crucial part was understanding how, even as a trained therapist close to my family, they still managed to infiltrate," she said. "I knew how important finding those answers were.
I felt it wasn't just about my son anymore, it's about other people's families as well."
Friday's conference, which featured several panels and discussions over the course of the day, was the result of a partnership by the university and its Center for Terrorism and Security Studies, the Middlesex Coalition for Children and Operation 250, an organization that works to promote education about terrorism and hate groups.
Tyler Cote, Operation 250's director of education, said he hoped to bring greater understanding to the "massively misunderstood" topic of online radicalization.
"We just want to get teachers, community leaders, police officers in a room to start having these conversations because they are happening," Cote said. "A lot of people think the only way to deal with terrorism is to use a military, but if we as a society work together, we can address it as well."
About 150 educators, university members and law enforcement leaders attended Friday's conference, which featured half a dozen speakers. Wakefield Police Chief Richard Smith spoke about the efforts of hate groups to target students. Ian Elliot, senior quality and outcomes specialist for the United Kingdom's Ministry of Justice, and J.M. Berger, an author who studies extremism, hosted a panel about how terrorists use the internet target vulnerable youth as recruits.
Those online efforts extend well beyond Islamic terrorists to other forms of hate as well, particularly on the far right, speakers said Friday.
"There's a lot of pressure on (social-media) companies to start policing the far right on these platforms," Berger said. "The problem is the far right is a part of mainstream politics in Europe and the United States right now. Who decides who's in the mainstream? Whose tweets are encouraging extremism and whose tweets are being a part of the Trump administration? This is a judgment calls that someone has to make."
For Benyahia, her son's radicalization came as a surprise. Her contact with her son did not end when he traveled to Syria, however. Through WhatsApp, she began to hear from him a few months after he left.
She was faced with an impossible situation. The young man she thought she knew was now off fighting with a terrorist organization, but she was his mother. Even in those circumstances, he would act like a son, asking his mother if she thought it was OK for him to use a motorbike that one of the terrorist leaders had and what she thought about a girl that the group wanted him to marry.
Benyahia, who as a therapist works with 14- to 25-year-olds, had to walk a tightrope: If she grew emotional, Rasheed might push away, but if she ignored or disowned him, he might never want to return.
To get herself through occasional calls with Rasheed without breaking, Benyahia would pretend she was talking to him while he was simply away at college. No one outside of the police and her immediate family knew what was happening -- she would step away at work or take calls on a city bus in which her son, on the other line, described fleeing for his life from drone strikes.
"In one sense, I felt I didn't know him, but in another sense, he was my son still," she said. "I knew the only way to get him back or change his mind was that relationship. The only thing I had on my side was my bond with him that they couldn't break."
Benyahia sensed a different tone in her son's voice after he had seen the horrors of war up close, things "he did not expect." And then, on one call in the fall of 2015 as he prepared for another deployment, she could tell something no parent could ever imagine: they both sensed it would be the last time they ever spoke.
"All I could keep saying to him was, 'I love you, I love you.' He just kept repeating it," she said. "What is he going to say? There aren't words for it. You're not prepared for this. Parent books don't prepare you for anything on this scale."
Several weeks later, Rasheed's father got a brief call. His son had been killed by a drone strike.
Benyahia carried Rasheed's story around for months and months after his death, not telling anyone outside of police and her close family about his radicalization. But she eventually decided that she needed to speak up, so she founded her organization and began a campaign of advocacy.
"I broke that silence," she said. "I felt I'm not going to be ashamed of this, I'm not going to feel guilty, I'm going to speak about this, because I felt if I could speak out, I wouldn't be under their control again. I felt that they're not going to win. They took my son, but they're not taking me and my daughters as well."