A previous case...
http://www.bailii.org.../Admin/2006/1904.html
"A formal caution is a serious matter. It is recorded by the police; it should influence them in their decision whether or not to institute proceedings if the person should offend again; and it may be cited in any subsequent court proceedings. In order to safeguard the offender's interests, the following conditions must be met before a caution can be administered -
-there must be evidence of the offender's guilt sufficient to give a realistic prospect of conviction;
- the offender must admit the offence;
- the offender (or, in the case of a juvenile, his parents or guardian) must understand the significance of a caution and give informed consent to being cautioned. …
Note 2B A caution will not be appropriate where a person does not make a clear and reliable admission of the offence (for example if intent is denied or there are doubts about his mental health or intellectual capacity). …
Note 2D: In practice consent to the caution should not be sought until it has been decided that cautioning is the correct course"