Reasonable grounds to suspect or believe

The adjective ‘reasonable’ imports an objective standard and requires facts and circumstances which would lead an impartial third party to form the belief or suspicion in question. In a civil action arising out of the exercise of a power which requires a reasonable belief or suspicion, the question whether there were reasonable grounds will be decided by the judge, as it will in the rare criminal cases in which the question arises (cf Herniman v Smith (1938)). In forming that belief or suspicion, the person is not constrained, as is a court, by rules of evidence. Consequently, inadmissible evidence may be taken into account; for example, hearsay, the previous character of the accused, including any previous conviction, or information from an informant.

The hearsay or information must itself be reasonable and the constable must be satisfied that it is true, or possibly true, depending on whether the standard is ‘believe’ or ‘suspect’. An anonymous telephone call would satisfy neither standard, and reasonable steps must be taken to verify that information.

How far the person should go in seeking verification also depends upon whether the standard is reasonable grounds to believe, or to suspect. It is argued that such inquiries are necessary to establish reasonable suspicion (or belief) but not when reasonable suspicion (or belief) exists and the discretion to exercise a power is available. One may then make further inquiries before acting, but one need not do so. Clearly the latter standard will be satisfied by taking fewer steps than will the former.

Informants are a regular source of information giving rise to a reasonable belief or suspicion. How much verification is necessary will depend in part upon the type of information, and in part upon the credibility of the informer. The more often the informant gives credible information, the greater his credibility and the fewer steps which need to be taken to verify it, although much will depend on the nature of the information and of the informant.

It has been suggested that information from a principal or accomplice in the crime cannot be the basis of reasonable cause to believe or suspect (Isaacs v Brand (1817)). If this was the ratio of that case, which is doubtful, it cannot in modern times be good law. As with the case of one party to a crime giving evidence against another party, one must be aware that the person has, or may have, a purpose of his own to serve and take appropriate steps to verify the information: see James v Chief Constable of South Wales (1991), where the court said that information derived from an informant should be treated with considerable reserve. However, the supplier of drugs or seller of stolen goods can often provide more reliable information than those who are not involved and who have a better reputation.

Where the information comes from fellow police officers, a constable may be justified in acting on it without any verification. For example, constable A hears a crash of glass at 2am. He turns a corner to see a shop window broken and a youth running away. He communicates this information, together with a description of the youth, to his radio operator who in turn passes it to all constables in the area. At 2.05am constable B sees D, who answers the description, running from the direction of the incident. Constable B has reasonable grounds to suspect that:

(a) an arrestable offence (criminal damage and/or theft) has been committed; and

(b) D has committed it.

He may then arrest him under S24(6) of PACE (Art 26(6) of the NI Order). Note that the constable is under a duty to tell D why he is being arrested, in effect to state the reasonable grounds justifying the arrest.

The above discussion applies to the other requirements of reasonable grounds to suspect or believe (or a similar formulation) whether contained in PACE or Order or other statutes. For example, an application for a search warrant under S23(3) of the Misuse of Drugs Act 1971 requires ‘reasonable ground for