I think the simplest way to answer this is that Julie tracked them because the script told her where they would be!
I know it's not a great answer, but there isn't a very logical explanation as to how she could have done it.
Some people over at the IMDB forums have had a discussion about this same issue. The nearest thing to any sort of explanation was offered by one of the posters:
When she locked one of the men in the closet, he told her how they
always used that room to play poker in. She would have been told
(or figured out) the projectory of the shot, she would have discovered
it came from that building and just bribe the tenants into finding out
who used that room even though the men never met there again. Money
opens doors as surely as doorknobs
I fully admit this is a little weak and requires a massive stretch, but she is intelligent and did have some five and a half years to plan the murders.
Having said that, I stick with my first comment. I think it largely happened because it made the script work - nothing more than that.
As to whether the men were indicted - there appears to be no evidence anywhere that they were.