R v Constanza [1997] is an English case reaching the Court of Appeal and is well-known (amongst other cases) for establishing the legal precedent in English criminal law that assault could be committed by causing the victim to apprehend violence which was to take place some time in the not immediate future, that it is not necessary for the victim to see the potential perpetrator of the violence, and that it was for the prosecution to prove that fear was in the victim's mind, but how it got there is irrelevant.

Mr Constanza was charged with assault occasioning actual bodily harm contrary to section 47 of the Offences against the Person Act 1861.

The case against him was that his behaviour was such as to cause the victim (Louise Wilson) to feel that his actions posed a threat to her personal safety.

The Court of Appeal also held that it is for the Crown (the Prosecution) to prove that fear was in the victim's mind and that it is irrelevant how it got there and that certain conduct accompanying words could make that an assault.

In case of further instances, argued or appealed successfully for the defence, based on remoteness of the truly feared action, Parliament, passing a government bill, introduced the Protection from Harassment Act 1997.