Understanding Actus Reus
Actus reus is simply the "guilty act" – the physical part of any crime. Think of it as the action bit that gets someone into legal trouble. It doesn't always have to be a dramatic action though; it can be an act, failing to do something (omission), or even just being in a particular situation.
There are three main types of crimes based on what the actus reus involves. Conduct crimes are straightforward – the illegal behaviour itself is the crime. Take drink driving: you're breaking the law the moment you drive whilst over the limit, regardless of whether you crash or hurt anyone.
Consequence crimes need something bad to actually happen as a result of your actions. For instance, with actual bodily harm under the Offences Against the Person Act 1861, you need to cause real injury – just threatening someone isn't enough. The key here is that your guilty act must directly cause the harmful consequence.
Quick Check: In the Marchant and Muntz case, even though someone died in a vehicle collision, there was no conviction because the driving itself wasn't actually dangerous – no guilty act, no crime.