A witness in the PC Keith Blakelock murder trial told the Old Bailey that "all blacks look alike" to him.
The witness, who is using the pseudonym John Brown, has told the court he saw Nicholas Jacobs stab the officer during the Broadwater Farm riots in October 1985.
When questioned in court if he thought all black people looked alike, Mr Brown answered: "More or less."
Jacobs, 45, denies murdering PC Blakelock, who was repeatedly stabbed by a mob in Tottenham.
The jury heard that during one interview with the police in August 1993, Brown, who has admitted kicking PC Blakelock up to ten times, was asked whom he had seen during the attack.
He replied: “It’s very hard for me because, like, I’m not a racist person but to me a black is a black. I can’t tell the difference between them. To me a black man is a black man.”
Asked by Courtenay Griffiths QC, for the defence, if he still thought all black people looked alike, the witness answered: “More or less.”
During the police interview Mr Brown, a former member of the Park Lane Boys gang, admitted he frequently carried a knife.
The jury also heard that before deciding to co-operate with the police, the witness had asked if he could get "a better house in a nice area" if he went into witness protection.
Mr Brown admitted he kicked PC Blakelock after receiving £240 to pay for car repairs, the court heard.
The trial continues.