There are three key elements which are necessary for the commission of most crimes:
Suitable targets (things worth stealing)
A motivated offender (someone who is able and willing to carry out the crime)
The absence of a capable guardian (something/one that might deter the criminal)
If any of these three elements is missing, then the crime is less likely to take place
Routine activity theory pt 2
The major rise in predatory crimes such as burglary after WW2 were related to the increases in routine activity away from the home (e.g. women were going to work) therefore the homes were no longer 'guarded'
Contact crimes (assault, robbery, pickpocketing) were also more common as there were more people out and about to come into contact with the offenders
Routine activity theory pt 3
The suggestion is that individuals should try to make it harder from criminals to access their possessions, avoid showing off valuable items in public and ensure it is well guarded