1,253. "Tearing Kriyah"

194:12 It is prohibited to handle the deceased on Shabbos, even for the needs of kohanim (who cannot enter if there is a corpse in the building) or for the needs of a mitzvah. The deceased may be moved by a non-Jew on Shabbos if the relatives so desire.

195:1 If a person lost a relative for whom he is required to mourn (i.e., parent, sibling, spouse or child), then he is also required to tear his garment for this relative. Tearing must be done while standing as per II Samuel 13:31, "Then King David arose and tore his garments." If one tore while sitting, he has not fulfilled his obligation and he must do it again while standing. Optimally, one should tear before the deceased's face is covered in the burial, while his grief is still intense.