Transcript for New details about Salman Abedi, suspect in the Manchester bombing attack

There are new developments this morning in the investigation into that horrifying suicide attack in Manchester, England. We're learning about red flags that may have been missed. New details about his life before the attack. All this as Ariana grande announces she'll perform a benefit concert for the victims and their families. ABC's mat out Gutman. Reporter: More red flags raised about Salman Abedi. In this interview with bbc. An official from the Abedi's mosque he was previously reported to police. A possibility has been shifted to the police and to the security services. Reporter: This morning, a friend of Abedi tells ABC news in 2011 he fought alongside a 16-year-old Abedi in Libya against the can dafi regime. They were part of the so-called Manchester brigade. Now more about Abedi's suspicious actives. Abedi slipped through the cracks. Today the British government saying there are 23,000 current and former suspects and 3,000 so-called live suspects. But law enforcements tells ABC they have the capacity to monthen or the 500 of them at a given time. This man's family member detained as officers stormed in. There were officers right at the door, pointing guns. Reporter: The raids go on. And this city still very jittery. Police cars swarmed this area, screaming get down, telling people to get back, shut off their phones. Reporter: It was a false alarm. As Manchester struggles to its feet, Ariana grande promising a return to Manchester for a benefit concert. Saying we won't let hate win. Folks here in Manchester city can't wait to welcome Ariana grande back for that benefit concert. While there's been immense outpouring here, the memorials. The police say the hate crimes against muslims have doubleds just since the bombings. As we come on air, the British prime minister reduced the threat level from critical to severe, that as we learn an investigators can't possibly monitor all 3,000 of those suspects at once. Only 1/6 of them. Dan and Paula. Matt Gutman thanks for your reporting this morning. As the holiday getaways begins, a terrifying incident in

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