Campion said Williams was “remonstrating with no-one in particular” and was shouting something but he “couldn’t tell you what he was shouting”.
“He just looked angry, you could see the anger in his eyes,” the witness said.
The trial also heard from witness Dinaria Soares who was sat across from footballer Jonathan Gjoshe, who jurors have heard was the first person attacked by Williams on the train.
She said she saw the knifeman “hit him on the shoulder… I was surprised and confused at first”.
Then when the attacker pulled his arm back she saw a knife, before describing a “stabbing motion had a lot of force behind it”.
The court heard she went to the front of the train where people were “trapped like sardines as there was nowhere else to move”.
Jurors watched a video interview with Malani Ranawake, who was travelling in carriage J where the court has heard Williams’ attack began.
She said she witnessed him stabbing a man and Williams said “I’m not going to leave anyone”.
Ranawake, who later hid in a toilet, said the defendant looked at her but “didn’t look cross or angry”.
During the prosecution opening, jurors were told Williams “has some mental health issues which may or may not become relevant during this trial”.
As well as arguing Williams was attempting to murder the 10 people on the train, prosecutors allege that on 31 October he tried to kill three people in Peterborough.
He is also charged with attempting to murder a teenager in the early hours of 1 November on a DLR train in east London.
Whether Williams carried out the attacks is not in question – the court has been told – but jurors must consider whether he intended to kill.
The trial continues.
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