James Chappell, 31, was jailed for four years and four months at the city’s crown court.
Kyrees Sullivan, 16, and Harvey Evans, 15, died in May 2023 when they crashed on an electric bike in the Ely area of the city.
The subsequent violence and disorder was sparked when news of their deaths and the suggestion police had been pursuing the pair prior to the incident spread throughout the community and on social media.
Judge Tracey Lloyd-Clarke, the Recorder of Cardiff, passed sentences for 30 defendants at Cardiff Crown Court on June 17, 18 and 19.
In her sentencing remarks, Judge Lloyd-Clarke said: “The loss of Kyrees and Harvey has obviously caused the most terrible grief to their families.
“The deaths of Kyrees and Harvey also brought grief to their community in Ely.
“As the terrible news began to spread, people gathered near the scene.
“Very soon rumours began to spread about the cause of the crash, including rumours on social media, and the police were blamed.
“More people came to join the crowd, not just those in the immediate vicinity but also from the surrounding area.
“Anger and hostility towards the police began to build.”
The court heard the crowd became openly aggressive towards the police as officers tried to expand the cordon around the scene of the crash.
Judge Lloyd-Clarke added: “The police officers at the scene were abused and threatened with violence.
“As the police were moving the crowd further back, some people in the crowd began throwing missiles at the police – bottles, bricks, stones, bits of plasterboard, and other items were thrown at the officers.
“The missile throwing continued for hours.”
The court heard the size of the crowd continued to grow into the evening and people filmed and live-streamed the escalating violence on social media, with cars being set alight and petrol bombs thrown.
A total of 31 police officers and one member of the public suffered injuries during the riot, ranging from bruising to sprained limbs and concussions, and “substantial damage” was caused to the community.
The riot continued until the crowd began to disperse at around midnight.
