He came to the authorities' attention when five-year-old Beth told her mother that he had sexually abused her. Geoff's parents reacted with disbelief. After the case went to court and Geoff was given a one-year supervision order they wanted to see the abuse as a "one off" which was best forgotten.
Sexual abuse of children is always shocking but never more so when the abuser is under the age of consent themselves. It is tempting to see such crimes as rare but they are not.
In 1993 almost a fifth of offenders found guilty or cautioned for sexual offences in England and Wales were under 18. That included 300 children aged 10 to 13 and 1,200 aged 14 to 17.
Conviction rates for sexual offending are low and it is likely many offences are not reported, so the rate may be considerably higher than the statistics suggest.
Those who start abusing when they are young can have a lifetime of abuse ahead unless they are counselled.
There are few services to deal with juvenile abusers however. One is the Kaleidoscope project in Sunderland, a centre run by the National Society for the Prevention of Cruelty to Children and Barnardos, which has just celebrated its second birthday.
"Geoff's parents wanted to see this as an abnormal event which would not be repeated," said Anne Blues, Kaleidoscope's child protection manager. "But that kind of behaviour doesn't go away. Studies of adult offenders show that many begin offending at an early age and without intervention are likely to commit multiple assaults over many years.
"Whilst everyone has the potential to change, this potential can be maximised with children and young people."
There are no quick solutions. Much time is spent getting the youngster to face the fact of their actions. Juvenile abusers, like adults, will often claim that they were led on by their victim, that the victim enjoyed it or that it was an occurrence that suddenly happened out of the blue. Not true, says Ms Blues.
"They may claim it was just rough-and-tumble games, that they haven't done anything but that is all part of the build-up. Then they'll claim that this event just happened - `I was just in the park having a pee and the child came into the bush' - and I don't know what came over me."
Those at Kaleidoscope work to break this cycle of abuse by intensive counselling so that the child accepts responsibility for what they have done, while bearing in mind that there are usually serious reasons - such as being abused themselves - which have caused them to do this.
What is difficult for many parents to accept is that the abuser will then spend a lot of time grooming their victim, befriending them and their family to build up an aura of trust before taking their opportunity.
Once the abuse has taken place there is a period of guilt. Inevitably the guilt is pushed away and the trigger may set off the next cycle.
Around eight to 12 one-hour sessions will be spent assessing the child. One counsellor will talk to the child about what actually happened while another monitors the child's reactions from another room. Counsellors are taught to ask "open" questions to draw out the child.
At the NSPCC's Coventry Project for young abusers Richard Gist, the area children's service manager, says the important thing is to work closely with parents as well as the child.
After assessing the child they work out a relapse prevention scheme so that the child learns to avoid situations where he might abuse again.
The numbers speak for themselves. Of the 75 children the Coventry Project has counselled in the past four years, only three have reoffended.
5 Geoff and Beth's names have been changed to protect their identities.