There is no evidence more than one person got into a van which ploughed into worshippers in Finsbury Park, a court has heard.
Prosecutors allege Darren Osborne, of Glyn Rhosyn in Cardiff, deliberately mowed down Muslims outside two mosques in north London shortly after 12.15am on June 19 last year.
Jonathan Rees QC, introducing further evidence for the prosecution on Monday, told Woolwich Crown Court: "It's directed at this issue, namely whether the defendant Darren Osborne acted together with other persons specifically a man called Dave and a man called Terry Jones to carry out this attack."
DC Hazel Londt, of the Metropolitan Police, showed the jury CCTV footage of the van from the minutes leading up the to attack.
Mr Rees said: "What you were looking at was any possibility that Mr Osborne was joined on this part of the journey by anyone else."
The images showed Mr Osborne returning to van, which was parked on Coleridge Road, at around 12.10am, until the moment of impact on Whadcoat Street at around 12.16am, the court heard.
Mr Rees asked her: "Have you detected any evidence that anyone else got into the van?"
Ms Londt replied: "No."
Mr Rees said one of the issues being considered was "how many people got out of the van after the incident occurs".
Ms Londt said CCTV footage of the aftermath shows the door of the van opening and a "stumbling" figure come out, adding that she could only see one person leave the driver side.
Osborne, 48, denies the murder of Makram Ali, 51, and attempted murder of "persons at the junction of Seven Sisters Road and Whadcoat Street, London".
The trial is set to continue on Tuesday.