The coroner at the inquest of Jean Charles de Menezes has told jurors to "ignore" a courtroom protest by family members.
Minutes before the jury was sent out to consider its verdict on Thursday, three of Mr de Menezes's cousins stood up and unveiled T-shirts displaying the message: "Your legal right to decide - unlawful killing verdict."
But as a second day of deliberations began, Sir Michael Wright told the 11 jurors they must not allow their considerations to be influenced by anything other than the evidence.
He added: "What was displayed was wrong and you should ignore it."
The coroner previously directed the jurors they can return only a verdict of lawful killing or an open verdict.
In front of the jury, the three cousins - Patricia da Silva, Alessandro Pereira and Vivian Figueiredo - stood up and unzipped their jackets to reveal the message.
The coroner said: "In any event, it's quite wrong for anyone to seek to put pressure on a jury and it should not have happened. To turn it upside down, to turn it on its head, just suppose the families of the police officers had come to court wearing T-shirts with particular messages seeking to influence you.
"You would readily understand that that was quite wrong and that you should ignore, and exactly the same applies here. I am very aware that these proceedings are stressful for a large number of people, and not just for the family of Mr de Menezes, but everyone relies on you to make your decisions only upon the evidence you have heard in court."
Mr de Menezes, 27, was shot dead by police marksmen at Stockwell Tube station in south London on July 22 2005 after being mistaken for failed suicide bomber Hussain Osman.
The Menezes family's legal team, led by Michael Mansfield QC and his junior Henrietta Hill, was absent from court when the jury returned to hear the coroner complete his summing up.
