For –

• If you take a life you should have your own life taken
• There should be a more harsh punishments for worse crimes, for example if there is someone who robbed a store, and someone who raped and killed someone the rapist and murderer should have a harsher punishment
• If someone is put into jail for life, if they know there is no harsher punishment they may kill again while in jail knowing they cannot be further punished  

Against –

• Everyone has a right to life
• It’s a two way street if someone kills then i killed them
• It depends on situations, if someone killed for a more ‘logical’ reason than someone who killed for no reason why should they get the same punishment