To an outsider, punishments which misbehaving teachers receive from England's General Teaching Council can seem inconsistent, if not bizarre.
Christopher Ogbe, of Bexleyheath school in Kent, for example, indecently assaulted a female colleague on a school trip and was jailed for three years.
Yet the head of business studies,received only a 12-month suspension when he appeared before the GTC last year after his release from prison.
A month before, the council gave a five-year ban to Michael Morrison, a teacher at Lea Valley high school in north London, for fabricating CV references.
The GTC has dealt with 61 conduct cases since March 2001. Defences offered by teachers who appeared before it range from being drunk, the pressure of league tables and mental and physical illness.
The National Association of Schoolmasters Union of Women Teachers and the Secondary Heads Association admit outsiders cannot know the full details of such cases. But both believe the system needs to be reviewed.
Chris Keates, NASUWT acting general secretary, said punishments for misconduct seemed more consistent before the creation of the GTC three years ago, when all cases were judged by a small team at the Department for Education and Skills. "Now that consistency is gone," she said.
Another issue of concern is whether the Government is passing on cases to the GTC which it should be handling itself.
A grey area surrounds the case earlier this month of David Walker, a history teacher jailed for two years for orchestrating soccer thuggery by using the internet.
Birmingham Council, his local authority, believed the decision about his future career would be handled by the GTC. The DfES says it is likely to decide the case itself, however.
The DfES and the GTC independently receive reports of misconduct from schools and councils and share them with each other.
The department is expected to handle all cases which "relate to the safety and welfare of children" or involve teachers not registered with the GTC - primarily staff at independent schools.
Charles Clarke, the Education Secretary, is empowered to place restrictions on teachers including adding them to List 99, which bans them from working with children. At least 416 have been added to this list since 2001.
By law, the Education Secretary must automatically bar anyone who commits a series of specified offences against under-16s, which include sex crimes, murder and taking indecent photographs.
Mr Clarke is also expected to judge cases where teachers are guilty of a sexual offence against someone over 16, offences involving serious violence, or "behaviour which indicates a risk to others".
But some teachers who have committed such offences have had their cases examined by the GTC.
Margaret Morrissey, spokeswoman for the National Confederation of Parent Teacher Associations, said parents would be worried if ambiguities in the system made it easier for serious criminals to work in schools.
"The last thing we would want to is to end the career of a teacher because they made a mistake - but that is different to someone committing a serious crime such as GBH," she said.
The average cost of a conduct case for the GTC is around pound;14,000, with an extra pound;9,500 spent when a solicitor is needed.
The GTC starts by setting up an investigating panel which examines whether there are grounds for a conduct hearing.
Those who sit on the hearing committees in Birmingham insist they take a balanced view of teachers' behaviour and reach consistent judgements. Canon John Hall, a committee member and the Church of England's chief education officer, said they had a duty of "compassion" towards teachers and the education service. "Sometimes that compassion requires a recognition that someone has made a mistake but is not ever going to do that again," he said.
This view is shared by the National Union of Teachers. John Bangs, its head of education, said the union had initial doubts about the tribunals but now felt they took a "360-degree view" of a teacher and their behaviour.
* The General Teaching Council for Wales has held three conduct hearings, taken no action in one case and given one suspension and one prohibition order.
The GTC for England has held 61 conduct and 10 competence hearings. These are the respective numbers of sanctions given so far:
Life-long prohibition order
Conduct two, competence nil.
Prohibition order (A ban for at least two years, after which teachers must prove to a panel that they are fit to return to the classroom) Conduct eight, competence one.
Suspension order (A maximum of two years, after which they may return to teaching without any further hearings)
Conduct eight, competence three.
Conditional registration order (Allowed to return to teaching immediately, provided certain conditions are met, such as their headteacher providing a regular report)
Conduct 21, competence three.
Reprimand (an official reprimand which remains on their records for a set time)
Conduct 14, competence nil.
No finding of unacceptable professional conduct or of serious professional incompetence
Conduct eight, competence three.