First of all you as a Muslim should avoid harming any innocent person. Just suspension about a person is not enough but concrete evidence must be known to you.
If a person tries to shoot you, you should try to protect yourself in every possible way. If you to protect yourself by shooting back, you should avoid killing the person as much as you can. You should never try to kill a person if you have any other way to protect yourself.
'I advise you to be away from a job which can lead you to kill any human being.
Wassalam.