Does a mourner tear one garment, or every garment he wears for a period of time?

Question

I belong to a liberal community and what I have seen, when somebody is in mourning for a parent, is that they wear a "kriah ribbon" instead of tearing an actual garment, and they wear it at least through the period of shiva (I can't remember if they wear it through sh'loshim). I am fortunate to not yet have direct experience in this area, nor have I learned the relevant laws, but a recent question here about that "ribbon" practice made me wonder what the traditional practice really is. (I am aware of the problems with the ribbon practice, which is why I want to know what's correct.)

I know that upon learning of the death one tears his shirt. Does the mourner do it that one time -- the commandment is to tear -- or does he wear a torn garment for some period of time to show that he is in mourning? If the latter, how long? Does he keep wearing the same shirt, or if he changes clothes (as we are more wont to do in modern times) does he tear the other ones too?

Answer 1

Shulchan Arukh YD 340:14

על כל המתים אם בא להחליף תוך ז' ימים מחליף ואינו קורע על אביו ואמו אם מחליף תוך ז' קורע כל הבגדים שהוא מחליף ואינו מאחה לעולם כמו בפעם הראשון.‏
Upon any [ordinary] death, if [the mourner] comes to change [his clothes] during Shiva, he may switch and not tear [again], [but] on one's father and mother, if he switches [clothes] during Shiva he tears [again] all the clothes that he changes [into] and doesn't fix [the tear] forever, just like the first time.

This is also the practice cited in Arukh haShulchan (ibid. 14) and in The Jewish Way in Death and Mourning. I often see mourners (not just children) wearing the same shirt for the whole week of Shiva.

Answer 2

The above is correct but in addition, for a parent, one tears on the left, the side of the heart. For the other 5 relatives (brother, sister, spouse, or [R"L,] son or daughter), one tears on the right side.

Also, it is inappropriate to show such an intense form of mourning on Shabbos or after the Shiva. To clarify, this is only appropriate for the shiva, unless the Kri'ah was never done (or the ribbon was used, which is insufficient.) In a case where someone did not do the Kri'ah, either because he wasn't aware of the requirement or because he just heard about the loss after the Shiva was concluded, he should do the Kri'ah on that day only.