Mwangosi, 40, a reporter with the private television station Channel Ten, was killed during a confrontation with police over the arrest of another journalist, according to news reports and CPJ interviews with three journalists who witnessed the shooting.
Mwangosi, who was also the chairman of the press club in the southern city of Iringa, was covering a demonstration by supporters of the opposition party Chadema (Chama cha Demokrasia na Maendeleo) outside Iringa, news reports said. The demonstrators had gathered in Nyololo village in defiance of a ban on political demonstrations imposed by the police, according to news reports.
Police attacked Mwangosi after he confronted them about the assault and arrest of Godfrey Mushi, a reporter with Nipashe newspaper, local journalists told CPJ. Mushi had been photographing the demonstration and the police, local journalists said.
Neville Meena, secretary-general of the Tanzania Editors' Forum, told Reuters that police fired a tear gas canister into Mwangosi's stomach at close range. One widely circulated photo appeared to show an officer pointing a rifle at an individual being held down by several officers. The scuffle was documented by several local journalists, including Francis Godwin and Gustav Cheha.
Authorities initially sought to avoid responsibility. In a statement, Iringa Police Commander Michael Kamuhanda said that Mwangosi died from a heavy object that had been thrown by demonstrators, according to news reports. Reuters quoted national police commissioner of operations Paul Chagonja as saying that "police deny any deliberate involvement in the death of the journalist."
News accounts reported that Home Affairs Minister Emmanuel Nchimbi announced the creation of a five-member special commission chaired by a retired judge to investigate Mwangosi's death and produce a report.
Mwangosi is survived by a wife and four children. His was the first work-related fatality documented by CPJ in Tanzania since the organization began keeping detailed records in 1992.