Alan Bright, known as John, committed a campaign of abuse over two decades, a court heard
A former school caretaker has been jailed for 15 years following a "campaign of sexual abuse" lasting two decades.
Alan Bright, 79, of Almond Way, Colchester, Essex, was convicted of 22 counts including rape, indecent assault and gross indecency.
During sentencing at Chelmsford Crown Court, he was told by the judge: "Your abuse was relentless".
Essex Police said Bright "put his victims through hell".
"It has personally been one of the hardest cases I have dealt with," said Det Con Cornelius Bowen.
The earliest instance of abuse was when Bright groped a 10-year-old girl on a ghost train at a funfair, the court heard.
Judge Patricia Lynch QC said Bright had "manipulated children in the course of [his] daily life" and abused his position of trust by committing the offences between about 1970 and 1990.
Hide and seek
The jury heard he had spent years manipulating children "under the guise of playing games" such as hide and seek.
Prosecutor Kate Davey said Bright, who went by the name of John, had also volunteered his services to look after his victims by offering lifts and on one occasion taking a girl on a trip to the seaside where he abused her while swimming.
Ms Davey said Bright had exhibited "classic grooming behaviour" by giving his victims presents and games, and that there was evidence he had manipulated daily events to maximise his exposure to girls.
The judge said some of Bright's victims had suffered post-traumatic stress disorder as a result of his actions.
She sentenced him under the guidelines of the Sexual Offences Act 1956, which was in place when he committed the offences, but added that under the current sentencing regime, Bright's prison term would be considerably higher.
