The Metropolitan Police is to continue using Taser' stun guns following a 12-month trial.
Tasers were trialled for 12 months
The force was one of five that took part in trial of the weapons, which ended this month.
The guns, which fire two barbs delivering an electric shock, are classed as a "less lethal" option to conventional weapons.
Tasers have been used a number of times during the trial period but officers say they have not always worked.
Met Commissioner Sir John Stevens it was important to make sure the weapons did work properly and that there was further debate to be had over the disciplinary process surrounding officers using them.
But he added: "The actual pulling of the trigger is nothing to do with supervising officers, it is your decision to pull that trigger and you are held totally responsible.
"I think it's worth further debate because it's not something that's going to go away."
The Tasers will not be carried routinely by all officers.