Killing someone needs to be carried out with high quality roleplay, if they've turned up and decided to rob you, told you to put your hands up etc, and you comply. It would be very bad if they then shot you in the head as they ran away with 0 reason. however if they have a strong roleplay reason for wanting you dead, after they provide a good high quality experience for those involved they are free to kill you, again only if they have a good reason to within roleplay. Making some shit up about being homicidal maniac is not really good enough to just kill someone.
There is also the following rule (G2.5) Compliance - If someone complies with your demands you may not kill them, unless they were involved in an illegal transaction. (Sale of drugs/weapons/dirty cash)
This rule means if you put your hands up and follow their commands during a robbery for example they cannot simply shoot you at the end for the fun of it.
Hope that cleared this up.
