Director of Public Prosecutions, R (on the application of) v Glendinning

Warning motorists of a police speed trap constitutes obstruction only where the warning could affect motorists who were speeding or were likely to speed. The prosecution must establish actual obstruction, lawful execution of duty and an intention to obstruct. A warning intended to prevent crime is distinct from one intended to suspend or postpone offending during the period of danger of detection. Where no relevant motorist was speeding or likely to speed, there is no obstruction of the police, even if the warning was intended to alert motorists to the trap.

The Director of Public Prosecutions appealed by way of case stated from the Crown Court at Taunton. The Crown Court had allowed the respondent’s appeal against his conviction for obstructing a constable in the execution of his duty by warning motorists of a police speed trap.

The Crown Court found that no motorist seen in the relevant video was exceeding the speed limit or likely to do so, and that no vehicle had reacted to the signal. It therefore ruled that the prosecution had failed to prove obstruction. The question for the High Court was whether proof that warned motorists were speeding or likely to speed was necessary.

1. The appeal was dismissed. The question stated for the opinion of the High Court was answered in the affirmative.
2. For wilful obstruction of a constable in the execution of his duty, the court must ask: whether there was an obstruction; whether the constable was acting lawfully in the execution of his duty; and whether the obstruction was intended to obstruct the constable in that duty. The three-question approach in Rice v Connolly [1966] 2 QB 414 was applied.
3. The officers were lawfully operating the speed trap, and the respondent intended to warn motorists of it. The essential question was whether there was any actual obstruction. On the facts found, no motorist who could have been affected by the signal was speeding or likely to speed. Accordingly, the signal could not obstruct the officers’ duty to detect speeding motorists.
4. The court followed the ratio identified in Bastable v Little [1907] 1 KB 59. A warning directed at conduct which was not then being committed, and which was not likely to be committed, did not obstruct the police. The case was distinguishable from Betts v Stevens [1910] 1 KB 1, where motorists were already exceeding the speed limit and the warning prevented the police from obtaining confirmatory evidence.
5. Green v Moore [1982] 1 All ER 428 was distinguished. Its reasoning concerned a warning designed to suspend or postpone offending until the danger of detection had passed. That analysis did not apply where there was no evidence of any motorist speeding or likely to speed.

• High Court (Administrative Court): answered the stated question in the affirmative and dismissed the Director of Public Prosecutions’ appeal.
• Crown Court at Taunton: allowed the respondent’s appeal against conviction and ruled that there was no case to answer because no relevant motorist was shown to be speeding or likely to speed.
• South Somerset Magistrates’ Court: convicted the respondent of obstructing a constable in the execution of his duty.