most asassins kills are from the back, but all of them are possible if your enemy doesnt know your there. So even if you get them from the front, you can kill them in one shot.
I don't know how to a knife kill in Fireteam Bravo 1, but for Fireteam Bravo 2, sneak up behind him/her and on top of your reticle will have a square button and the word beside it is "Knife". The goal is to maintain stealth. You can only do the knife kill when you are behind the enemy. For Fireteam Bravo 3, you cannot do a knife kill. You can only do something called a Stealth Kill. Sometimes stealth kills include knife. If you do a stealth kill, you might first choke him from behind and then stab him with a knife 3 times. The goal is to maintain stealth.
You can kill someone with a rusty knife because 1st its a knife and 2nd it has rust . If the knife didn't kill them the disease from the rust would only if they didn't get a shot for it.
http://www.cheatcc.com/psx2/gtasa.html ---- Take a knife (not the katana) then crouch. Sneak behind someone and target them. You will see Carl holding his knife very high once you are near the target. When that happens press the fire button and he will kill the victim instantly.
9 killstreak
its 10 kills
No you can't make stealth kills with your hands. In fact the only way you can make a stealth kill is with your hand blades.
with a knife
With a knife.
You can kill the mermaid by stabing her with a knife
The book just describes it as "a kitchen knife"
"stealth boys" , find and kill some nightkins they usually have one or two.
a knife