Re: Correctional officers during salah
If I know the person, that is a different story. I will speak to him about what I know afterwards but of course in private.
If I do not know the person, I will try to get to know him by starting with salam. Once we know each other properly, I will some how try to convey the message indirectly or directly and of course in private. Often, I would have involved the scholar/imam at masjid to touch upon the subject in general terms in his sermon.
What scares me is that I will be questioned by God about it and why I did not try to correct it in my own capacity. We as muslims are called witness over the mankind in Quran and it is a very scary thought if we do not fufil the duty of being witness 
but at the same time you do not want be singled out as religious police and custodian of Islam. It’s difficult to keep the balance but you gotta do what you gotta do.