A senior Metropolitan Police officer has been found guilty of possessing an indecent image of a child.
Supt Novlett Robyn Williams was sent a "disturbing" video by her sister Jennifer Hodge last year, but failed to report her, a court heard.
Hodge, 56, and her partner Dido Massivi, from whom she had received the video, were both found guilty at the Old Bailey of distributing an indecent image of a child.
All had denied the charges.
Williams also faced a charge of corrupt or improper exercise of police powers in failing to report the distribution of an image, but was cleared of this.
Massivi, 61, was found guilty of two counts of distributing indecent photos and guilty of possessing an extreme pornographic image.
Williams, 54, from south London, was one of 17 people sent the video by social worker Hodge, from Brent, in February 2018, the court heard.
Massivi previously told the jury he sent the video to his long-term partner "for awareness" after a colleague sent it to him.
Hodge said she threw her phone "in the shock of it" when she opened the video and sought to speak to her sister, who "might know a little bit more than [her]" about getting it taken down.
Her sister, however, claimed she had never seen the video.
The Met officer, who was highly commended for her work helping families affected by the Grenfell Tower disaster, told the court she had "zoned out" when she received it.
But prosecutors said there was no way Williams could have missed the 54-second clip, and cited a response from the officer to her older sister to "please call" as evidence that she wanted to discuss the content.
Police were alerted by another recipient, rather than Williams, who as a senior police officer had an obligation to report it, the jury heard.
Prosecutor Richard Wright QC previously told jurors it was not suggested the defendants had any sexual interest in the video that showed a five-year-old girl engaging in a sex act with a man.
Instead, he said, "each of them made serious errors of judgment about how to handle this video".
Deputy Assistant Commissioner Matthew Horne said the police watchdog the Independent Office for Police Conduct (IOPC) was carrying out an independent misconduct investigation into the actions of Supt Williams.
Williams remains on restricted duties, Scotland Yard said.
Sentencing will be held on 26 November.