Without more details on the incident I am not sure how I feel about how it played out. For personal safety, it might have been better to be a solid witness and note as much detail as I could about the suspects without engaging, but the sheepdog in me wants to engage, without violence preferably, and prevent their escape from the scene so that police can apprehend them. Based on what is briefly said, I don't believe there was a way to non-violently engage so then I would have to just be the witness since engaging would put myself and others at risk. Unless they were to engage first as is indicated but others being shot as well as the good samaritan.