Speaking to Lusa, Francisco Mapanda, or Dago Nível, as he is best known, said he saw the young man lying on the ground, with "his skull pierced" and loss of blood and brain mass.
Doctor Augusto Manuel told TPA public television this Thursday that the young university student, Inocêncio de Matos, 26, died from head injuries caused by a "blunt object" that could have been "a stick, a piece of metal, of iron", rejecting the version of being shot by a firearm.
On Wednesday, the day the police frustrated an attempt at a demonstration in Luanda that resulted in several confrontations with young people, reports and videos posted on social networks pointed to the existence of a death that was denied the same day at night by the authorities.
Dago Nível told Lusa that he was with Inocêncio de Matos "Beto", in a group that left the Rangel neighborhood and tried to access the city center, towards Largo 1 de Maio, where the demonstration was expected to end, having passed several police barriers.
"Beto' fell at the fourth barrier, where the police did shots," said Dago Nível, explaining that he met the student that same day.
"I didn't know the young man personally, he was my first contact and unfortunately the only one," said the activist, adding that 'Beto' faced the police "fearlessly and bravely".
According to the activist, the police tried to prevent the demonstrators from accessing the main road in various ways, firing shots and throwing tear gas to disperse the young people, who were advancing and crossing the police barriers.
At the fourth barrier, between the Cidadela and the Américo Boavida hospital, as they advanced toward Avenida Brasil, the police will have fired more shots to intimidate and contain the advance of the young people who knelt down and sang the anthem as a deterrent.
"There were many of us and they couldn't stop us, they started shooting into the air and into the ground and we knelt down and raised our hands as a way to inhibit the police and started singing the hymn," reported Dago Nível, saying that "Beto" was in the front row, with other youths, kneeling.
"They kept shooting and one of the bullets went into 'Beto''s head," continued Dago Nível, accusing the doctor of "making up a story.
The activist added that "Beto" didn't fall when he was running, but when he was kneeling.
"Then the young man fell, people surrounded him and started screaming: they killed, they killed. I was upset, I saw a hole in my head, I saw pieces of my brain, I realized I was dead," he testified.
"One of the 'brothers' lifted the body, but the police didn't want us to take the body, they took it," he assured.
The youths will have fled and entered the neighborhood to escape the police and "there will be no more fatalities, having been surrounded and stayed there for some time.
"It was the first time I saw this happen. Even José Eduardo dos Santos did not do it," lamented the activist, criticizing the repression of the protest, which aimed to demand better living conditions and local elections, by President João Lourenço "who proposed to change what is wrong" and in which the young people deposited "some credit".
"It's disgusting, I'm very upset," he said.
Dago Nível is an activist linked to the 15+2 case who was convicted and arrested for shouting in the Luanda court that the trial was "a clowning".
The 15+2 case concerns 17 young government activists who were arrested in 2015 while debating a book and accused of preparing a coup against the MPLA government of the then president, José Eduardo dos Santos.
Among them was the 'rapper' Luaty Beirão ("Iconoclasta") who also received an arrest order on Wednesday and was released a few hours later.
Dago Nível is currently one of the promoters of the 10Padronizada Library, an improvised street library under a footpath in Luanda that offers free reading.
