There appear to be four different kinds of mugger:

1)The 'snatch and run' mugger, who literally rips your
handbag/briefcase from your shoulder/hand and runs
away at speed, or even drives away on a bike.
2)The blind side mugger who suddenly appears
out of an entry without any apparent warning
3)The defiant mugger who attacks without ritual or
fear of the law or consequences, usually because you
have walked into his patch or have inadvertently
crossed his Path and he wants whatever you have got
4)The professional mugger who plans his
attacks and uses deception as a 'way in'.
Environmental awareness is the best way to avoid the first
three, but a thorough understanding of attack ritual is the
only real way of avoiding the fourth.