One is considered a mourner upon the death of the following relatives: father and mother, husband or wife, son and daughter, brother and sister (also half-brother and half-sister).
K'reeah (Rending of Garment)
To indicate grief, a cut is made in the outer garment or black ribbon worn by the mourner. For a parent, the rend is made on the UPPER left side downward over the heart; for other relatives, it is made on the right side downward. This ceremony is performed standing up to teach us to "meet all sorrow standing upright." This cut garment or black ribbon is work during the seven days of Shiva.
The ritual washing and purification of the deceased by memebrs of the Chevra Kadisha, "The Sacred Society," or, in its absence, by religiously and physically competent Jewish persons.