Burn any thing thay wore and use the cleaning suplys at there home so it doesn't look like some one else was there, also candle all of there mail and credit cards so it doesn't build up and people for get suspicious.
This kind of scared me, but it got my heart racing. I've heard a quote that says, "If it makes your heart race, do it".
UPDATE: it actually says, " If it makes your heart race, then you should probably do it."
you could also get a completely sterile suit (those that nuclear scientists use) and put it on (helmet and gloves too) and go to a public place but stay close to a building. shoot your victim with a gun you stole from someone that has no connection to you at all. you quickly enter a building and burn the suit,helmet and gloves. leave the gun where it is, police will suspect the person it belongs to, buying you time to leave town or something until they close the case. take the ashes to a lake or forest or dumpster far outside of town and get rid of them. proceed to get a cold beer and celebrate a successful murder
Mythbusters did the entire suit thing and it didn't seem to fool the dogs. Also, leaving the building would create a scent trail.
Or, y'know, you could avoid the problem in the first place and not murder people
Jk
UPDATE: it actually says, " If it makes your heart race, then you should probably do it."
Or, y'know, you could avoid the problem in the first place and not murder people