The vengeance of a murder victim in Halacha:
The unprecedented, horrific and harrowing pogrom on Simchas Torah, which has left over 1000 Jewish men women and children savagely murdered in cold blood by a barbaric inhumane enemy, has rightfully boiled the blood of anger and vengeance within Jews in the world in general and in Israel in particular. While in general, vengeance and revenge are negative traits that are to be mitigated and restrained according to Torah law, nonetheless, when it comes to a murder victim, Jewish law amplifies the necessity of the people to seek vengeance from the murderers and for even the soul of the victim itself to venge its death from the enemy and not rest until the murderer is brought to justice. The following are the laws relevant to this context:
No Taharah-Burial in same state found: A murder victim is to be buried in the state that he is found. He is not to have Tachrichin placed on him [and does not go through the Taharah process]. None of his clothing is to be removed, not even his shoes. [If the victim was murdered by a gentile, then this applies even if the murder victim does not contain open injuries which release blood, such as if he was drowned or strangled.]
The Tachrichin: As stated above, the murder victim does not have his clothing removed and thus does not have Tachrichin placed on his body in their stead. Some Poskim, however, rule that the Tachrichin is to be placed above the clothing. Practically, the custom is not to make the same Tachrichin for the murder victims, as is done for others who have passed away, but rather to bury them in their clothing and then place a [white] sheet over them as is done for others who pass away.
Blood stained clothing and earth: All material that has absorbed the blood of the victim, such as clothing and earth, is to be buried with him. Hence, the custom is to dig around the area that the murder victim was found and to bury that earth together with the body.
|Burying the victim with a knife:
Some are accustomed to burying a murder victim with a knife in his hands, representing the fact that he will avenge his death. It is forbidden to get benefit from this knife if the body becomes unearthed.
The murder weapon:
It is forbidden to get benefit from a murder weapon, such as a murder knife, and it is to be buried with the victim.
The murder victim does not rest until the murderer is killed:
The soul of a murder victim does not rest in heaven until their murderer is apprehended and held accountable. The soul of the victim demands justice and that his murderer be put to death, and does not rest his case until this is done. This is the secret meaning of the verse “One who spills blood of man, his blood will spill” as the prosecution that the soul of the victim voices against the murderer, brings about the death of the murderer, and if not in this world then in the next world. This can be seen with the story brought in the Midrash that after a certain son was murdered by his brother, his mother saved the blood in a jar, and that blood boiled until the murderer sibling was killed. It is for this reason that we do not perform Taharah to the victim, as burying the victim in the clothing of his murder helps motivate him to seek vengeance against the murderer.
Saying Hashem Yikom Damo:
It brings satisfaction to the soul of the murder victim when one says “Hashem Yikom Damo/May Hashem avenge his death” after mentioning his name.
 Michaber Y.D. 364:4; Hagahos Maimanis end of Aveilus in name of Rabbeinu Ephraim; Shach 364:11; Taz 364:2; Mavor Yabok Sefas Emes 10; Chochmas Adam 157:12; Kitzur SHU”A 197:12; Gesher Hachaim 11; Darkei Chesed 13; Nitei Gavriel 48:6-7
 The reason: The reason for all the above is because a person with an open wound which releases blood needs to have the blood buried with him, and thus we avoid cleaning him and changing his clothing, which would wash away the blood. [Shach 364:11; See Taz 364:2] Likewise, in addition to above we bury the murder victim in his current state because we desire to arouse anger and avenge his death. [Shach 364:11; Taz 364:2; Bach 364; Kitzur SHU”A 197:12] It is for this reason that we do not perform Taharah to the victim, as burying the victim in the clothing of his murder helps motivate him to seek vengeance against the murderer. [Mavor Yabok ibid]
If his clothing were already removed: See Birkeiy Yosef 364:1 in name of Shelah, and other Poskim brought in Nitei Gavriel 48:7, that in such a case a regular Taharah is performed and he is garbed in Tachrichin. Nonetheless, the clothing is buried with him.
Died in prison: See Birkeiy Yosef 364:1
 Shach 364:11; Taz 364:3; Bach 364; Mavor Yabok Sefas Emes 10; Chochmas Adam 157:12; Kitzur SHU”A 197:12; Gesher Hachaim 11 [see there regarding if he only died later on of his injuries]; Nitei Gavriel 48:6
The reason: This is due to the second reason mentioned above. [Poskim ibid]
If murdered by Jew r”l: The above ruling is written regarding if the victim was murdered by a gentile. Vetzaruch Iyun if he was murdered by a Jew and there are no open injuries.
 Opinion in Rama ibid; Hagahos Maimanis in name of Rav Yehuda Midura
 Rama ibid
 Shach 364:11
 Sefarim brought in Nitei Gavriel 48 footnote 7
 Sefer Chassidim 1013; Mavor Yabok Sefas Emes 10
 Azharos Nosafos of Rav Yehuda Hachassid in Tzavah 6; See also Sefer Chassidim 1013 and Mavor Yabok ibid; Nitei Gavriel 48:13
 Mavor Yabok Sefas Emes 10
 Midrash Raba Vaeschanon
 Mavor Yabok Sefas Emes 10