The use of police cautions for criminal offences in England and Wales is to be reviewed, the government has announced.
Cautions, issued at the discretion of police, are a way of sanctioning criminals without going to court.
But concerns have been raised that they are being used to deal with repeat offenders and for those who commit serious crimes, contrary to advice.
The Association of Chief Police Officers (Acpo) said a "measured view" should be taken on the issue.
The review will look at the way cautions are used and consider whether there is any need for changes to current laws or guidance.
Last year more than 200,000 people who committed crimes were cautioned.
The vast majority of those received a formal warning from police about their conduct, following an admission of guilt.
A formal caution is normally given at a police station by an officer of inspector rank or above. It is not a conviction, but is regarded as a serious matter and may be cited in subsequent court proceedings.
This review has not been prompted by an increase in numbers, says BBC legal correspondent Clive Coleman. The use of cautions has fallen by 42% over the past five years.
Instead, it is driven by concerns that, contrary to guidance given to police, they are being used to deal with serious offences and repeat offenders, says our correspondent.
Policing Minister Damian Green said the review would look at why serious or repeat offenders were being offered cautions, and why there appeared to be regional differences among police forces.
"Serious and repeat offenders shouldn't expect to escape with a caution," he said, adding that the guidelines have been updated to clarify that.
He said there were guidelines for exceptional circumstances where a caution was appropriate even for a serious offence, such as the mental health or the age of the offender.
"You do have to give that ultimate decision to the police office involved, but in terms of having overall confidence in the system, cautions should only be given for low-level or first-time offences," he told BBC Radio 4's Today programme.
In the most recent annual figures covering offenders who were either cautioned or found guilty in court, more than one in four people involved in violence against others, and one in five sex offenders, received cautions, including 19 cautioned for rape.
The Association of Chief Police Officers lead spokesman on cautions, Chief Constable Chris Eyre of Nottinghamshire Police, said caution decisions were not made in a "cavalier" fashion but by "sensible local officers".
"It's really important we take a measured view on this and make sure everything that goes on is working to ensure our communities are safer.
"Crime is coming down across communities. We are increasing public satisfaction in police services and we are increasing public confidence. That is because considered decisions are being made which are right in the circumstances locally."
Mr Eyre gave examples of a 17-year-old having consensual sex with a 15-year-old, or teenagers carrying a knife on a fishing trip, to demonstrate where a caution may be appropriate.
However, the chairman of the Magistrates' Association, John Fassenfelt, said his group, which has about 28,000 members and represents more than 80% of serving volunteer magistrates, had been appealing to the government for about four years to deal with the issue of cautions.
"They are not being used for the reason that they were introduced for," he said.
He said that one reason for the use of cautions could be that they are "cheaper" for police as "they don't have to prepare so much paperwork to bring it to court."
"My argument is that every crime has a victim, and every victim deserves some paperwork. If you think that 11,00 individuals were cautioned because of violent crime last year, therefore there were 11,000 victims. None of those victims got compensated by the court."
Javed Khan, chief executive of Victim Support, said victims wanted "the response to fit the crime".
"Although it is up to the police to decide on when to use cautions, victims need to have confidence in these decisions and to have them clearly explained," he said.
"The police also need to be clear on when it is appropriate to give a caution - for example, this is not likely to be right for most violent and sexual offences."
The Police Federation of England and Wales welcomed the review, with Paul Ford - a member of its Inspectors' Committee - saying: "Cautions are a useful option for minor offences, and in some cases first-time offenders.
"At times there are much wider factors that are taken into consideration when giving a caution, including the wishes of the victim or whether the offender is a young person."
But he called for the review to include other offender management options, such as penalty notices, community interventions and charging, describing them as "interlinking issues".
The Ministry of Justice (MoJ) said the review followed calls for "greater public confidence and transparency in police use of cautions for repeat offenders and for those who commit serious crimes".
In a statement, the MoJ said it would examine:
- Existing guidance and practice relating to cautions
- Whether there are offences where use of cautions would be "inappropriate" - and if so, what should be used instead
- Reasons why multiple cautions are given to some criminals
- The difference in their use by different police forces - and whether increased scrutiny is needed to ensure they are used consistently
- The impact on individuals of accepting a caution, including how it might affect future employment
The MoJ said it was working with the Home Office and Attorney General's Office, and the review would closely involve the police, Crown Prosecution Service, victims' organisations, the judiciary and the legal community.
The review will report back to ministers by the end of May.