Lou, owner of the Malamute Saloon in Redding, won't talk to me. I've dumped every party member thirty yards away from the entrance of the bar and she still won't talk. I need to find out who cut the pro! Can anyone help me?

If I remember correctly, talking to Lou is not necessary to find the killer. You just miss the dialogue from Lou (In case you didn't save upon arriving at Redding).

Thank you, Weclock and Alai. If I could mark both posts as solutions I would.

hehe, yeah

i'm having this same problem, yet i never talked to lou with a non-human NPC in my party! i think i may have encountered a bug... let me explain.
i did have harold's assistant (leonard?) in my party at one point. i was in new reno with him, and i came across angela bishop. it was pretty easy to get her to sleep with my character, i just agreed to do some jet. there was a ton of good loot in her place; however, getting out was very tricky. i managed to run out of the shark club alive and keep the loot. but here's the weird part -- my ghoul NPC just disappeared. couldn't find him in new reno, and i went back to gecko to find him. no dice. i assumed he ran off or something.
so when i talked to lou, she said that she refused to talk to me with a "freak" around, yet i had no one with me!
anyone else run into this before?
EDIT: well, it turns out that there is a bug -- sleeping with angela and then saving your game on the third floor of the shark club will cause your NPCs to disappear. i guess a flag that harold's assistant was with me was still active when i talked to lou. i'll just deal with it... there's no way i'm reloading back that far, especially after the insanity it was to blast/run my way out of the shark club.