Death Spells are a category of black magic spells in hoodoo/rootwork, as well as just about every tradition of magic, which are performed to bring about the death of a person.
The following are my personal opinions. Practitioners are bound to disagree with me and that is perfectly fine.
In my opinion, death spells are a lost cause. The amount of power needed to actually magically kill a person outright is simply beyond most people. This said, there are indeed tales of people who somehow managed to conjure the power necessary to bring it about. Usually this is a result of the person experiencing a sever injustice and the power and drive for revenge is strong enough to manifest as actual death of the enemy.
It is my belief that there are two basic types of death spells. The first type is the spells performed with the intention of actual magical murder. The second type is unintentional magical murder. The difference between the two is that in the second type, a curse that one performs manifests as the death of the individual, even though this wasn't necessarily the intention of the practitioner. Now, with regard to the first type of death spells, such are the ones most likely to fail due to lack of power needed to manifest the desire. In order to remedy this, many dark-sided practitioners will invoke, command, or make pacts with various spirits. There is a price to pay for such work. These types of spells that require the invocation of dark spirits also tend to require animal sacrifice of some sort, usually in the form of the animal playing the role of a "living voodoo doll". This means that the animal is abused and tortured before dying a horrible death in order to bring such pain, suffering and death to the person. Sometimes a real "voodoo doll" or doll-baby may be used in place of the animal, and such is often buried in a miniature coffin in a graveyard with the accompanying petition to the spirits to drag the person underground. There are also a myriad of other rituals or spells that are similar in nature to what I described above, such as nailing a tree instead of harming an animal, but it would be rather pointless to discuss because these types of spells generally fail.
The only hint I will give to anyone foolish enough to attempt a death spell would be to say that it is quite silly to think that one simple spell will result in some one's death via magic. To be blunt, if your spell has any hope of being successful then it will need to be a work-in-progress, something that is regularly worked on in order to weaken the person to the brink of, and eventually past, the point of no-return. Be warned. The practitioner will be attuning his/her life to the forces of destruction and such is sure to manifest in their everyday life. To put it another way, it would be like leading a person to the edge of a bottomless pit, with both the practitioner and the enemy teetering on the edge and with the practitioner attempting to push the enemy down without falling in them self. It's a very hard task to accomplish.
I will end on this....you would be surprised about the people who truly want to perform these spells. Even certain bible-thumping, born-again, non-occult practicing Christians have performed black magic death spells. A few years back there was a story in the news about a Christian group holding prayer sessions in which they prayed for the death of certain politicians. Anybody who practices magic or is even mildly interested in the occult should automatically realize that praying for someone to die is black magic.
See Also VOODOO DEATH