Romeo Daley was born on September 15, 2002 and was 18 years old at the time of his conviction in early 2021, suggesting a birth year around 2002 or 2003. Like his co-defendants, Daley was involved with AO (Active Only), a gang operating out of the Moss Side neighborhood in Manchester. AO was considered one of the successors to Manchester’s older and more violent criminal groups, the Gooch and Doddington gangs.

On 26 July 2020, the feud between Manchester’s AO and Rusholme Crips reached a violent tipping point. Around 7:30 p.m., police responded to an emergency call on Henbury Street, in Moss Side. When officers arrived, they discovered that four young men had been stabbed. Among them was 17-year-old Mohamoud Mohamed, who died at the scene. The others were treated for non-fatal injuries.

Investigators quickly tied the attack to the escalating gang war. Just a month earlier, the same neighborhood had experienced a deadly shooting that killed two people, and police believed these were not isolated events. The Moss Side stabbing appeared to be a planned retaliation or an ambush influenced by ongoing gang tensions.

Romeo Daley, along with Jamall Walters (18), Daneaco Reid (19), and a 17-year-old accomplice, was arrested the next day and charged with murder. During the investigation and trial, prosecutors pointed to drill music videos made by AO members. One chilling line stood out in court: "I swear that's Mo, let’s kill him, kill him...", seemingly referencing the victim directly. These lyrics were used to demonstrate both motive and intent.

On 12 February 2021, Daley and the three other defendants were convicted of manslaughter.