All perfect praise be to Allah, The Lord of The Worlds, and may His peace and blessings be upon our Prophet Mohammad and upon all his family and companions.
It is prohibited for a person to discharge a gun in celebration of a certain occasion because it frightens people, and the Prophet (PBUH) said in this regard: " It is not lawful for a Muslim that he frightens a Muslim." {Abu Dawood}. Moreover, this act violates the state`s laws and regulations which ban such a thing, fulfill public interest and maintain peace and security. Whomsoever commits such an act must refrain stop immediately, make repentance, seek forgiveness and guarantee whatever befalls people or property.
In addition, if this act has led to someone`s death, then it is considered accidental homicide, but involves carelessness and underestimation of human life, and this is forbidden. Therefore, the killer must pay the Diyah (blood money) and the Kaf`fara(expiation), which is fasting two continuous months. Allah, The Almighty, said {What means}: " Never should a believer kill a believer; but (If it so happens) by mistake, (Compensation is due): If one (so) kills a believer, it is ordained that he should free a believing slave, and pay compensation to the deceased’s family " {An-Nisa`/92}. Finally, the judge is at liberty to choose the discretionary punishment (Ta`zeer) that he sees fit to make an example of such a person. And Allah knows best.