The father of the victim, a guy who was executed by the Taliban in front of the public for the first time since they retook power in Afghanistan,
According to a Taliban spokesman, the man was slain at the southwest Farah province's crowded sports stadium.
According to a later statement from the Taliban spokesperson, the victim's father shot the man three times during the execution.
The shooting was attended by many of the group's leaders.
It happens a few weeks after judges receive orders to completely implement Sharia law.
Haibatullah Akhundzada, the Taliban's supreme leader, issued the directive last month, instructing judges to impose penalties that may include public beheadings, public amputations, and stoning.
The Taliban hasn't, however, publicly codified the particular offenses and related punishments.
Although there have been several recent public floggings, including one last month in front of a packed football stadium in Logar Province, this is the first time the Taliban have openly admitted to carrying out an execution.
According to their spokesperson, Zabihullah Mujahid, the execution was observed by several Supreme Court justices, military personnel, and senior ministers, including the justice, foreign, and interior ministers.
Also present was Mohammad Khaled Hanafi, the Taliban's minister of vice and virtue. He was responsible for carrying out the Taliban's strict application of Islamic law. According to the statement, prime minister Hasan Akhund stayed home.
The Taliban stated that Mustafa was stabbed five years before his execution by Tajmir, a citizen of the Herat province and the son of Ghulam Sarwar.
Mullah Akhundzada approved the verdict after three Taliban tribunals ruled him guilty.
Before the execution, a press release announcing the occasion and "inviting all citizens to join us in the sports field" was released.
According to the mother of the deceased, she refused to pardon the man despite Taliban commanders pleading with her to do so.
She said, "The Taliban came to me and begged me to pardon this unbeliever." They beg me to pardon this man for the glory of God, but I tell them that he must be put to death and buried in the same grave where he killed my son.
This could teach other individuals a lesson, she suggested. "He'll do more awful things in the future if you don't kill him."
The Taliban were denounced for regularly carrying out penalties in public, including executions at the national stadium in Kabul, between 1996 and 2001.
The Taliban swore never again to subject women to such terrible tyranny. Women's freedoms have been severely restricted since they acquired power, and several women have been physically assaulted for calling for rights.
No nation has yet to recognize the Taliban's new government because they barred girls from returning to secondary schools, and the World Bank has withheld over $600 million (£458 million).
In addition, the US has blocked billions of dollars in assets held in accounts worldwide by the Afghan central bank.
