Valeria Khadija Collina last spoke with her 22-year-old son, Youssef Zaghba, by telephone just two days before he and two other men plowed a van into a crowd near London Bridge and went on a stabbing rampage.
As more victims of Saturday's attack were named, a minute's silence was held across Britain on Tuesday morning as a mark of respect for those killed or injured.
Despite a rapid response to Saturday's deadly attack, which saw armed officers shoot dead all three suspects within eight minutes, opposition parties have called for May's resignation for her cuts to police numbers.
London attack: What we know so farWho were the attackers? They believe they may have unwittingly helped him obtain some components used in the device after he asked them to make the purchases.
Italian news reports said authorities sequestered Zaghba's cell phone and passport when he was stopped at the airport, but that he successfully got them back after a court determined there wasn't enough evidence to accuse him of any terrorism-related crime.
Zaghba visited her at her home near Bologna several times and in March 2016, after being stopped at Bologna airport, he was investigated for possible global terrorist activity but released, according to the newspaper.
He was then stopped from continuing his journey to Istanbul.
However, unconfirmed reports suggest he was placed on the Schengen Information System (SIS II), a vast database of alerts about individuals and objects of interest to European Union law enforcement agencies. Italian authorities tipped off Britain about his movements.
Jibril Palomba, anotherneighbor, said he spent time with Butt at the gym, where they spotted each other while lifting weights and boxed as sparring partners.
Scotland Yard has been criticised for the way they handled intelligence about Butt, who had been investigated by police and MI5 and featured in a Channel four documentary on extremism.
Video Islamic expert urges 'appropriate' response
Police also said Butt had tried to hire a 7.5-tonne lorry hours before carrying out the attack, but was turned down because the payment failed.
A second attacker, Rachid Redouane, 30, has been named by police. He married a British woman in Dublin in 2012 and lived in the city's Rathmines area.
The massive police probe into the attack continues and by today, 20 arrests have been made and 13 buildings searched. Redouane had not aroused any suspicions. London Bridge remained closed along with the Borough subway stations, while police were actively looking for suspects.
There were also office chairs, a suitcase and two bags of gravel which Haydon said might have been to add weight or to act as a cover story for their activities to friends and family.
London attack ringleader Khuram Butt was identified as a major potential threat, leading to an investigation that started in 2015, United Kingdom counterterrorism sources tell CNN. Her family have described her in a statement as an "outgoing, kind and generous person". "We will do our very best to try and keep them safe", he told local media.
"He was always exhausted", Melissa said. Relatives in Pakistan, meanwhile, said he had brought shame on to the family.
A London police spokesman said: "We haven't released anything at the moment, nor are we confirming anything but as soon as we are ready to name him, it will be on our website". The Prime Minister also said there has been too much tolerance for radicals.
Each of the men carried an identical blade as they inflicted the outrage on Borough Market.
"From his face, from his look, I could see there was a radicalization, as you say". "He was hit in the neck with a knife".
"I can only assume they were part of trying to cause fear amongst people who came across them", the senior officer said.