That would depend on the who. The one thing to always consider that if your only goal is to kill a person and nothing else its pretty hard to stop you. If you wish to live after you have killed a person well now things take a little effort.
Whoever invented the hammock and anyone who tried to create it afterwards. Fucking things are dangerous.
By all means add the how and the why to make it more interesting, the question then is how you'd get away with it. Oooh Jesus, now there's a topic for controversial discussion. I don't think Jesus was the problem, it's what the fanatics have done with organized religion since Jesus spread the word that's the problem. Poor bastard, if only he knew.
First thing, a complicated plan is a plan that will likely fail. Okay Sabot rounds leave no proof of the weapon it came from plus a sabot round extends the range of the ammo. A .308 round 165gr can reach out 1000 yards (10 football fields). Carlos Hathcock (Whitefeather) using a .308 confirmed kill around 2500 yards (25 football fields) Now we (the US) has changed over to the .50 cal for sniper weapons. The .50 cal range is 3000 yards (30 football fields) and if you factor in sabot rounds and a good shooter this could easily be extended out to 4000 yards or 2.4 miles. So for me the choice would be long range kill. Can easily do your job from over a mile away. This buys you time, the noise will disperse direction so harder to pin point location of shot fired, sabot round confuses investigation as to caliber and distance.
It'd have to be either in warfare or indiscriminate. The worst I could do for myself is murder out of ressentment.
An icicle might make a good weapon for bludgeoning or impaling, as the evidence melts after use, but then that puts you next to the victim, so you'd need to litter the site with various sources of DNA to confuse the forensics. Mind you, I'm not capable of killing anyone, the idea makes me sick to my stomach, but... Senator Phil Gramm might be a good candidate, being the mastermind behind the deregulation that led to the Enron scandal and the mortgage crisis, proving once again that left to their own devices corporate greedheads will consistently do the wrong thing. Gramm will probably be McCain's economic advisor if the unthinkable happens in November, but I digress.