Seriously?
So an armed police officer makes a mistake, in a very stressful situation and you would lock him up for life?
Most deaths of civilians where the police are involved does not include the use of firearms on either side. Most are somewhat unexplained deaths in custody or when under restraint. There are far more deaths of members of the public when in custody of the police than police officers killed in the pursuance of duties. Here for clarity I’m not talking about armed civilians being disarmed or contained – I’m talking about unarmed people losing their lives where they shouldn’t be at risk of death.
Where firearms are used, the training and the directions given should prevent such a mistake. It should be a controlled situation. We shouldn’t be shooting people carrying chair legs for instance… Besides, armed officers make very few mistakes historically.