Wayne Couzens was a gun and porn-obsessed 'weirdo' who was rumoured by his police colleagues to be a 'pervert'.
He was just 14 when he shot a classmate with his father's air gun, laughing out loud as the boy screamed in pain.
His behaviour was so alarming that Warwick Lewis, a former school friend, said he was not surprised to discover that the married father-of-two had been charged with the murder and kidnap of marketing manager Sarah Everard, 33, in March.
'The fact I was not shocked, looking back on it, is pretty hideous,' he said.
Couzens, a Scotland Yard firearms officer, appeared to be a devoted family man with a successful career guarding Westminster VIPs.