Tasers were made so that police officers don't need to use force in delicate situations which could become dangerous. As much as possible, in any encounter that the police have with people who have a tendency to become aggressive or violent, it would be best not to use force at all. But what happens if the equipment doesn't work?
...a yearlong investigation by APM Reports shows Tasers are often less effective than the company has claimed. And just as Tasers can save lives when they subdue suspects, when they don’t, the outcome can be deadly.