The police have the powers under section 24 of the Police and Criminal Evidence Act 1984 (PACE) to arrest without warrant for arrestable offences; these section of PACE, like all the other sections has many subsections. I have found seven subsections to section 24, these subsections break down under what conditions that a police officer may arrest somebody without a warrant and what an arrestable offence is.
A police officers can arrest anyone without warrant for offences for which the sentence is fixed by law and to offences for which a person of 21 years of age or over (not previously convicted) may be sentenced to imprisonment for a term of five years...; and to the offences to which the words 'arrestable offence' applies.
A police officer may also arrest anyone who is conspiring to commit any 'arrestable offences' or attempting to commit any such offence [other than an offence under section 12(1) of the Theft Act 1968], a police officer is also within his duties as an officer of the law to also arrest anyone who is inciting, aiding, abetting, counselling or procuring the commission of any arrestable offences.
The police are within there rights under PACE, to arrest anyone who is in the act of committing an arrestable offence or if the police officer has reasonable grounds for suspecting that any person may be committing any arrestable offences.
If the police officer has reasonable suspicion that a person has committed an arrestable offence, a police officer may arrest then if they are guilty of this offence and again if the police officer has reasonable grounds for suspecting the person id guilty of committing an arrestable offence he may also arrest them.
In section 25 of PACE, the general arrest conditions are laid down in which...