Where is the guard that gives you the 'Blood on the Ice' quest?

I just encountered that glitch on the xbox. I didn't do any Dark Brotherhood quests, so I don't know how that affects the game, but this is how I got around it.

Forget looking for the guard; if he hasn't come yet, he wont. Go to Hjerim and pick the lock (or in your case, open it with the key you got from Tova).

Once inside, you can't interact with anything at first. Instead it should say "inspect item". Go ahead and inspect everything in the house. You should find a couple of butcher journals, a bunch of "Beware the Butcher!" fliers, a Strange Amulet, and the Butcher's mess beyond the fake wardrobe.

Once you've inspected and picked up enough evidence, the quest should move onto the next step and proceed as normal. You can confront Viola (the woman making the fliers) or any of the guards with your evidence.

One more thing - if you picked up the Strange Amulet, it's marked as a quest item and can get stuck in your inventory. The only way of getting rid of it is by taking it to Calixto's Curiosities and selling it to Calixto. The amulet is not required to finish the quest so don't worry about selling it.

The guard is usually there around midnight, but if he's not use the key that you took from Tova Shatter-Shield's body to enter Hjerim. Towards the back of the house is a small dresser with fliers about the murder on it. Take one and the quest should start midway through the questline.