The Westminster attacker appeared to be holding a large kitchen knife above his head as he ran towards Parliament, says a journalist who witnessed yesterday's events.
Andrew Woodcock, political editor of the Press Associatoin, said "a man appeared to break away from the crowd" as the chaos unfolded, and then proceeded to run into the gates of Parliament.
Woodcock saw the carnage unfold from his window, as a car ploughed into pedestrians on Westminster Bridge before its driver got out and attacked a policeman with a knife.
Woodcock told Sam Delaney: "I heard a lot of shouting and screaming outside.
"There was a crowd, I would guess of about 40 to 50 people, running from the direction of Westminster Bridge up towards Parliament Square. They appeared to be running away from something.
"As they went past Carriage Gate, which is the big vehicle entrance at the front of the Houses of Parliament, a man appeared to break away from the crowd.
"He was holding what looked like a large kitchen knife in his hands above his head. He ran in through the gates, into the Parliamentary precinct."
Listen to the audio above