London attacker was a peripheral figure in previous MI5 probe - UK PM May

During her statement to the House of Commons on Wednesday's Westminster terror attack on Wednesday, the UK PM Thersa May said one attacker was responsible for the deadly terror incident and it is believed that the attacker acted alone. 

May added that a British-born man was inspired by Islamist ideology and that the attacker was a peripheral figure in previous MI5 probe in relation to concerns about violent extremism.