Mujianto was 24 years old and living in Nganjuk Regency, East Java, when police named him in February 2012 as the man behind a run of deaths that stretched back to the previous September. Police said five men had died. By the end of that month, 23 men had come forward to say they were victims. In November 2012 the Nganjuk District Court sentenced him to nine years in prison. He was released in August 2018 after a remission granted for Indonesian Independence Day.
The articles of the Criminal Code under which he was tried have never been made public, and how the court related the verdict to each death is not on record.
Mujianto came from Jatikapur village in the Tarokan district of Kediri Regency, according to the Jakarta Post and the Indonesian news site JPNN in 2012. The Jakarta Post gave his age as 24 when police announced his name. His date of birth, schooling and work history are not on record.
At the time of his arrest he was living in the Berbek district of Nganjuk Regency.
Police said the deaths began in September 2011 and continued until early February 2012. A detikNews summary of February 20, 2012 listed five dead by district. All the places named were in Nganjuk Regency, in districts including Tanjung Anom, Loceret and Prambon, with Pace also listed. The men who died came from other parts of East Java.
The dead whom the press named were these. Ahyani, aged 46, was from Situbondo. Romadhon, aged 55, was from Ngawi. Sudarno, who was also called Basori, was from Ngawi and was 42 according to the 2023 detikJatim account; the Jakarta Post in 2012 did not give his age. Wiji Subekti was from Kediri; detikNews placed his death at Pace on September 17, 2011. A fifth man has never been publicly identified; detikNews placed him in Prambon district in September 2011.
Sudarno's death was placed on February 4, 2012, and one further death was reported by the Jakarta Post for February 8. The dates the press gave for Ahyani and Romadhon differ: the Jakarta Post reported them in January 2012, while detikNews listed both in February 2012. Those two deaths are dated only to early 2012.
A Jakarta Post report of February 16, 2012, counted four dead and two survivors. By February 20, detikNews counted sixteen incidents across Nganjuk Regency and the districts around it, with five dead. Police told reporters that the fate of some of the men involved was not yet clear.
Nganjuk police ran the inquiry, and their chief at the time, Adjunct Senior Commissioner Anggoro Sukartono, spoke for it in the press. The detikJatim retrospective of 2026 says the case came to light through a man who survived, and that police later circulated a sketch of the suspect.
Nganjuk police opened a complaints desk for men who believed they had been harmed. On Friday, February 24, 2012, a 25-year-old man from Probolinggo Regency came to the desk and reported that something similar had been done to him in the Pace district in August 2011. JPNN reported on February 26 that 23 people had by then come forward, and that five of them had died. The police chief said the account matched the pattern in the other cases.
Police arrested Mujianto early on the morning of Monday, February 13, 2012, in Nganjuk Regency. Police held a press conference at Nganjuk police headquarters on Wednesday, February 15.
On February 20, detikNews reported that a preliminary examination of his mental state had found him fit. The same report said he had been aware of what he was doing. On February 24 Liputan6 reported that he had apologized to the victims and to their families. The Jakarta Post wrote that police were considering several counts of premeditated murder. That wording is the police's, and the charge on which he went to trial is not on record.
The Nganjuk District Court appointed a panel of judges to hear the case in 2012. The prosecutor asked for eight years in prison. On Tuesday, November 13, 2012, the panel sentenced Mujianto to nine years, a year more than the prosecutor had requested. detikJatim reported in 2023 and again in 2026 that Mujianto accepted the verdict and said he regretted what he had done.
The offence of which the court found him guilty is not on record. Whether the court related the sentence to all five deaths or to fewer is not on record either, and no appeal is on record. What is on record is that the court sentenced him to nine years' imprisonment.
According to detikJatim, Mujianto was released on August 17, 2018, from the Class IIB prison in Nganjuk. He was among about 100 inmates freed that day on remission granted for Independence Day. No later event is on record, and neither is his present home.
Several points stay unsettled. The counts differ between reports. The Jakarta Post of February 16, 2012 spoke of fifteen men and four dead; detikNews on February 20 counted sixteen incidents and five dead; JPNN on February 26 and detikJatim in 2023 spoke of 23 people and five dead. The later figure of 18 survivors comes from the 2023 and 2026 detikJatim accounts.
The dates of two deaths differ between reports. The relation between the verdict and the individual deaths is not on record, and the charge is not on record. The Jakarta Post wrote that the offences under investigation carried a maximum of twelve years.
September 2011: first death placed by police, in Nganjuk Regency.
September 17, 2011: death of Wiji Subekti placed at Pace.
Early 2012: deaths of Ahyani and Romadhon (January or February; reports differ).
February 4, 2012: death of Sudarno, also called Basori.
February 13, 2012: Mujianto arrested.
February 15, 2012: police press conference at Nganjuk police headquarters.
February 24, 2012: another man comes forward at the complaints desk; Mujianto apologizes to victims and families.
February 26, 2012: JPNN reports 23 people have come forward, five of them dead.
November 13, 2012: Nganjuk District Court sentences him to nine years.
August 17, 2018: released on remission.