Failures by MI5, the police and the probation service all contributed to deaths in a terrorist attack at Fishmongers’ Hall in London, an inquest has concluded.

Jack Merritt, 25, and Saskia Jones, 23, were unlawfully killed in the attack at a prisoner education event at the hall in November 2019, the inquest jury at the Guildhall in London found.

The jury also concluded that “missed opportunities” in the way the attacker, Usman Khan, was investigated by the security services and the police in the run-up to the incident probably contributed to the deaths of the victims.

The jury agreed there was a failure in the sharing of information and guidance by those responsible for monitoring and investigating Khan.

Explaining this conclusion the jury noted: “Missed opportunities for those with expertise and experience to give guidance.”

It also referred to “unacceptable management and lack of accountability” by those monitoring Khan in the community.

The seven-week inquest heard that Khan was under priority investigation by MI5 after he was released on licence in December 2018. He had served eight years in high-security prison for trying to set up a terrorist training camp in Pakistan.

There was intelligence in late 2018 to suggest that he intended to “return to his old ways” and to commit an attack after release.

This intelligence was passed to special branch police but it was not shared with those responsible for managing Khan in the community, including his probation officer Ken Skelton and Prevent officers at Staffordshire police.

Khan’s risk to the public was discussed at the regular multi-agency public protection agency arrangement (Mappa) meetings, some of which were attended by MI5. Khan’s invitation to the Fishmongers’ Hall event was raised at the meetings, but there was no record of any discussion about it, and none of the agencies involved raised any objections to his attendance.

Khan was allowed to attend the event unaccompanied, despite signs he was becoming increasingly isolated and frustrated at failing to find a job, the inquest heard.

The jury found that failings and omissions in way Khan was managed in the community was also a contributory factor in the deaths of Merritt and Jones.

Explaining this conclusion it said: “Serious deficiencies in the management of Khan by Mappa, insufficient experience and training.

And the jury concluded deficiencies in the security arrangements at the event, which was organised by Learning Together, a prisoner education organisation run by Cambridge University, also contributed to their deaths. The inquest heard that Khan was regarded as “poster boy” for the Learning Together programme and recorded a promotional video at an earlier event.

The jury said the authorities had a “blind spot to Khan’s unique risks due to ‘poster boy’ image and lack of psychological assessment posts released from prison”.

Usman Khan during a ‘thankyou’ video message for a Learning Together event in Cambridge in March 2019.
Usman Khan during a ‘thankyou’ video message for a Learning Together event in Cambridge in March 2019. Photograph: Metropolitan police/PA Media

On the organisation and security of the Fishmongers’ Hall event, the jury said: “Lack of communication and accountability, inadequate consideration of key guidance between parties. Serious deficiencies in the management of Khan by Mappa and the failure to complete event-specific risk assessments by any party.”

The jury offered its “heartfelt condolences to the families of Saskia and Jack”.

In a statement read to the inquest a spokeswoman for the jury said: “We want to convey to families how seriously we have taken our collective responsibility, how important this is to us, how much your children matter.”

She also paid tribute to people who attended the event, including former and serving prisoners, who fought off Khan during the attack.

She said: “We also wanted to take this opportunity to thank the astonishing individuals who put themselves in real danger to help, and our incredible emergency services for their response both that day and every day, once again to the families, we are so incredibly sorry. The world lost two bright stars that dreadful day.”

The coroner, Judge Mark Lucraft, will now consider setting out further lessons from the case in a prevention of future deaths report in the coming months. Such a report would make recommendations aimed at improving public safety and is likely to be critical of the security services and probation.

On Friday Lucraft opened a separate inquest into Khan’s death.