I understand this quest is pretty buggy but on my first pass through it worked. On my second time around I sold the amulet back to the killer to see if it changed anything. Well it did. Now I can't progress the quest. Is it required to have the amulet to move the quest along? The steward is marked as my target as i've investigated the house but he has no quest dialogue.

Talk to Wuunferth

Did you arrest the mage? If so, you bugged the quest. Selling the amulet is good since that will actually make it useful.

I spoke to Wuunferth but nothing really happened. He didnt have any quest dialog either. I'm gonna try Viola, maybe I need to tap her first?

Arresting the mage just turns it into a two part quest, you have to return to the city later and find out the murders are still happening which lets you back into the quest to find the real killer, it's what I had to do the first time I did this quest.

I"m foxed too. I arrested the mage and he went to prison. Out or curiousness, I went back a maybe 20 game hours later to chat with the mage & I found a chat entry "There has been another murder". The mage told me to patrol the stone district that night because another murder would happen. So I spent I dunno how many real hours in an area I was led to by the game arrow & nothing occurred.

I seem stuck. Anybody have the mage instruct him to patrol the streets and if so, where and what should I do?

So you went into the house and got the amulet, did you also investigate the chest and secret room?
What does your quest log say?

Edit: By the way, you MUST have a copy of the "beware the Butcher" flyer in your inventory otherwise Viola will not talk to you.

You could just stand in front of the inn near the main gates until you get a message to catch the killer, he will be running towards you from the market area where the smithy is, then turn left and take the path towards the house via the cemetary.

I got bored last time I did it and walked to the market just in time to see him sneaking up on a High Elf lady then stab her in the back.

I'll try that. I don't like leaving a quest undone or I'd just drop it. Thx.