William Unek (died 20 February 1957) was a Ugandan serial mass murderer who killed a total of 58 people in two separate spree killings in the Belgian Congo (modern-day Democratic Republic of Congo) and Tanganyika Territory (modern-day Tanzania) during the mid-1950s.

While living in the Congo, William murdered 22 of his relatives in a mass stabbing in Mahagi territory during a family reunion, apparently believing they were responsible for sabotaging his marriage using witchcraft. Though wanted as a fugitive by Belgian authorities, he had managed to flee the country for Tanganyika, where he took a new identity and became a police constable under the British administration.

After around two years, William, suspecting his new spouse was having an affair with his boss, targeted numerous places in and around his new home in Malampaka village in a mass shooting and axe attack, killing 36 people. Following a nine-day manhunt, William was fatally wounded during his capture. His true identity and connection to the earlier murders in the Congo were discovered a month later.

Background According to the East African Standard, William Unek's name is composed of a given name (William) and his father's name (Unek) as a patronymic. As such, he was typically referred to only by his first name, including in formal settings, i.e. "Constable William" rather than "Constable Unek". Reports on the 1957 manhunt described William as a "Uganda man", with the East African Standard identifying him as an ethnic Acholi, which was repeated in later publishings by The Times.

A joint investigation between Congolese and Ugandan authorities determined that William Unek was an alias and while he was of Ugandan origin, "William" was born Adrogo Urwinyo, an Alur of the Jahoulur chiefdom in Okoro County, West Nile District. The Alur kingdom, which is located in an area spanning the northeastern Congo and northwestern Uganda, had an arrangement with colonial authorities that allowed the Alur a degree of autonomy, including self-regulated border crossings through individual chiefdoms.

Mahagi killings On a Saturday night in either February 1954 or mid-1955, Adrogo had invited 22 family members to a banquet on the occasion of an indigenous festival, taking place at his home in Angala village, part of Angal chiefdom in Mahagi territory, located near the northern Congo–Uganda border. After the celebration, 20 of the relatives went to sleep while two children went outside to play. Adrogo then used a machete (commonly misreported as an axe) to kill each of the sleeping guests. He then set the home on fire and fled, encountering the two children on their way back in the neighbourhood and murdering them as well. Enabled through the late hours on a weekend day, he obtained a boat at Lake Albert to cross back into his native Uganda.

Despite an extensive search and numerous inquiries by Congo authorities to the Ugandan administration, the fugitive was never found. The killings notably caused shock with both the native and the colonial population.

Victims and motive The 22 victims were all related to the perpetrator, although English sources only reported 21.

According to Belgian Congo authorities, Adrogo had blamed close relatives for infertility during his second marriage, accusing them of "hexes". He was described as showing signs of neurasthenia, a broad and obsolete medical term characterised by physical and mental fatigue.

Escape to Tanganyika Adrogo eventually ended up in the Tanganyika Territory, where he gave the false identity of William Unek and claimed to be Acholi, another Luo people native to northern Uganda. The Acholi were regarded as a "martial race" by the British for their reputation as fighters and thus commonly assigned to military duty under colonial authorities. At the time, the vast majority of African law enforcement members in Tanganyika were Luo, whose languages, including those of the Alur and Acholi, are largely mutually intelligible. By 1956, William had joined the Tanganyika Police Force, who were unaware of his criminal past.Council Debates: Official Report (1957), p. 259 He was serving as an askari and held the lowest rank as constable. While it was known that William was from Uganda, no further background check had been performed on his entry into the territory.

In August 1956, William was stationed to Lake Province, residing and working in , a village in the province's Maswa District (in a part of the modern-day Simiyu Region). Malampaka is part of Sukumaland and located roughly halfway between the cities of Shinyanga and Mwanza, about southeast of the latter. William, along with his concubine Angelina (commonly misrepresented as his wife in international media), lived behind the police post, where the homes of other askari were located. William was described as "always quiet and reserved".

William spent most of the day before the attack at a pombe club and an Indian-run bar, which was considered outside of his usual behaviour.

Malampaka killings

Police outpost On the night of 10–11 February 1957, William committed a second spree killing. Just after midnight, William came into work at the Malampaka police post, located outside of the main residential area. He asked two superior officers, Sergeant Clement and Corporal Opiyo, to accompany him into town, asking them to help in the arrest of "a man who had several diamonds". The officers walked outside in single file fashion with Clement at the front and William in the back. During the trek into town, William struck Opiyo in the back of the head, causing the latter to lose consciousness for about 15 minutes. Upon awakening, Opiyo found Clement and William gone. Opiyo headed back towards the post to get other askaris to aid in search of both of the missing men. Opiyo and his colleagues then heard gunshots near Malampaka's Central Line railway station, where they found two dead men, whom Opiyo identified as the native assistant station master and a labourer. Senior Inspector M. C. Desai later found Clement's body in a hedge around from the police post. Both Clement and Opiyo had been attacked with an axe.

After attacking Opiyo, William had broken into the police armoury, using the axe to break the door open. A Sikh contractor, Ragbir Singh Lamba, later found the armoury door forced open, with the bloodied axe lying nearby, as well as six rifles and 50 rounds of .303 ammunition missing. In a house behind the armoury, Sgt. Clement's son was found wounded by a gunshot; the boy died despite first aid. A fire had been set in the adjoining hut where William and his concubine lived and inside, the burned bodies of two women and a child were recovered. At Opiyo's residence, the corporal's wife and three children were found shot dead. Shortly after 8:00 a.m., police heard three gunshots at the Malya road and found three dead men at the scene.

Town proper According to a witness, after William entered town, he "seemed to just shoot anybody who crossed his path". Investigators assumed that William had snuck up on most of the victims as the majority had been shot at a close distance. He shot various people outside and some employees at a local business, reportedly burning down a second hut before fleeing. The killings took place over the course of less than twelve hours.

Immediate reports counted nine dead and nine wounded at the scene. The same afternoon, the motorized sections of Mwanza Police, led by the Assistant Commissioner of Police Lake Province, started the search for William in the area near . The death toll rose to 16 the following day, with unconfirmed reports of 32 injured.

Surrounding area On the night of 12 February, William also strangled a 15-year-old girl,32nd slaying, The Ottawa Citizen (14 February 1957) marking the 32nd fatality per official announcement on 13 February. Between 14 and 16 February, William attacked several isolated homes surrounding Malampaka. Police determined that William ambushed the occupants and would steal their clothes and food before setting the huts and outbuildings on fire and fleeing again. In these attacks, four people were killed by gunshots or slashes, bringing the final fatality count to 36. The search was now considered significantly more difficult as this also meant that William had discarded his identifiable constable uniform.

Victims 31 people were killed in Malampaka, with eleven of the victims killed in close vicinity of the police post. Around 30 others were injured. Five more people were killed in the countryside surrounding Malampaka during the manhunt. In total, William had shot dead ten men, eight women, and eight children, murdered five men with an axe, stabbed another one, strangled a teenage girl, and burned two women and a child.African killer still at large, The Times (16 February 1957)Berserk Slayer of 36 Sought, The New York Times (17 February 1957) The coroner's statement initially reported the number of people killed by William to 37, but this was returned to the original count less than two weeks later. They were members of the Sukuma people.

William's concubine Angelina was reportedly one of those killed, having reportedly been murdered before their house was set on fire. However, as of the coroner's opinion in March, police were still in the process of tracking her movements and whereabouts. It was initially claimed that Sgt. Clement's wife Paulino was amongst the victims, apparently killed with the same axe as her husband, and that William stole the key to the armoury from her, though she was later named as a witness to the coroner's opinion. Similarly, Cpl. Opiyo was also described as a fatality before his account of the killings was published in the media.

Motive On 15 February, during the manhunt, speculation suggested that William "may have gone berserk from taking drugs". According to William's later testimony, he had developed a one-sided rivalry with his superior officer Clement, whom he accused of having an affair with William's concubine Angelina. While this could not be proven, reconstruction by investigators showed that Angelina had travelled to Shinyanga on 9 February via train. William reasoned that he killed the remaining victims because they were "spying" on him. Oral tradition passed down in the Kwimba District reflected this as stating that William had been motivated by "social misunderstandings with his boss".Madulu, Ndalahwa F.: Changing Lifestyles in Farming Societies of Sukumaland: Kwimba District, Tanzania; Afrika-Studiecentrum, Leiden (1998) (p. 25)

Manhunt For nine days, the bush and swamp area in the districts of Maswa, Kishapu, and Kwimba, covering several hundred square miles,Annual Report of the Provincial Commissioners for the year 1957; p. 51, 59; Government Printer, 1959. was searched by 3,000 Wasukuma tribesmen and 200 officers of Tanganyika police. A single spotter plane cooperated with Mwanza Police on the second day of the search. By 14 February, police reinforcements had come in from Tabora. The following day, military aid was invokedReport by His Majesty's Government in the United Kingdom of Great Britain and Northern Ireland to the General Assembly of the United Nations on the Administration of Tanganyika (1957); p. 10; Colonial OfficePublic Order, (1958); H.M. Stationery Office, p. 10; Issues 339-342 and a King's African Rifles company, numbering over 100 soldiers were sent over from Tabora via train, making the search for William Unek Tanganyika's greatest manhunt up to that time. By 18 February, the search force was 4,000 in total. British authorities posted a reward of £125 (US$350; ) for William's capture and deployed additional jeeps and aircraft to aid in the search.Other parts – Dar Es Salaam, The Calgary Herald (19 February 1957)