Protesting firefighters brought proceedings at City Hall to a standstill today, as they confronted Boris Johnson.
Mayor's Question Time had to be halted until order was restored - and all of it was witnessed by children visiting from a primary school in Croydon.
Carolyn Sim reports.
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"All it takes is for somebody to see me - and I could just die, just like that. I could want to go to the shop and not come home."
Before the killing, Peters searched the internet for "serial killers", "treatment of child killers in prison" and "premeditated murder".
Arriva Rail North, Greater Anglia and South Western Railway are all affected.