Frozen particles

I’m trying to do missile trails that are frozen in time. (so I can do matrix-style bullet-time shots) I’m working on a really hacky idea for it, but I thought I’d ask if there’s an easy way to do this. It’s just for cinematic sequences so if there’s something that will only work that way, it’s fine. I think ideally i’d want a way to freeze the particles from an emitter, but even if it removed any translation/rotation nodes they usually have a time-based opacity fade (so then the missile trails would go away as the shot progresses, or if i removed the opacity over time node, the trails would be solid all the way back). Thoughts?

Set your particle lifetime to infinite, then spawn particles as the head of the trail moves. That way existing particles will stay in place and not fade out.