British authorities have now identified all three of the suspects from the weekend terror attacks in London.
Police say they previously knew one as a possible threat, but one of the men wasn't on their radar.
Tuesday, they identified 22-year-old Youssef Zaghba, believed to be an Italian national of Moroccan descent.
Police said he is from east London, but he was not a "subject of interest" to police or the intelligence services.
Meanwhile, investigators had been concerned for years about 27-year-old Khuram Butt. He wanted strict Islamic Sharia law to be upheld in the UK.
A British TV documentary even featured Butt. It was called "The Jihadis Next Door."
He'd been seen on TV unfurling an ISIS flag. And a neighbor even called an anti-terror hotline to give a tip about his threats.
She had previously reported Butt because he had tried to radicalize her children.
"I don't know what kind of madness took him to do such a madness thing and leave two beautiful kids. I don't know, I don't know," said Jibril Palomba, whose wife had reported Butt.
Experts say these incidents led officials to ask if they could have stopped the attack.
"We always ask ourselves, 'Well, should we have known? Could this have been prevented?'" said UK counterterrorism expert Michael Clarke.
The Saturday night attacks with a van and knife in central London left nearly 60 wounded and seven people dead, including Canadian Chrissy Archibald and James McMullan of London.
"While our pain will never diminish, it is important for us to all carry on with our lives in direct opposition to those who would try to destroy us," said Melissa McMullan, sister of James McMullan.
In addition to Khuram Butt, a British citizen born in Pakistan, authorities have identified 30-year-old Rachid Redouane as a suspected terrorist in the attack.
Both men lived in the same east end London neighborhood.
Redouane is from Libya or Morocco.
Police fatally shot them, along with the newly identified third suspect, Youssef Zaghba.
London's Mayor Sadiq Khan, who is Muslim, spoke directly to terrorists.
"As a proud and patriotic British Muslim, I say this, 'You do not commit these disgusting acts in my name!" Khan said.
Khan and President Donald Trump got into a minor feud after the attack.
Khan says the British government should cancel an upcoming state visit by the president after Trump criticized him on Twitter for some of his remarks after the attacks.
While British Prime Minister Theresa May stood by the London mayor, she didn't comment on the president's statements.
After the deadly tragedy in London, coming on the heels of other recent terrorist attacks in the UK, the top British counterterrorism official says authorities plan to dramatically change their strategy.