By Aaron Ross

NAIROBI (Reuters) -When the policemen came for Albert Ojwang - the Kenyan blogger whose death in custody sparked protests this week and prompted a rare acknowledgement of police brutality by the president - his wife initially thought he would be safe.

Unlike the dozens of political activists abducted by suspected security agents over the last year, the 31-year-old schoolteacher was taken to a police station and officers shared their phone numbers with his family.

"When they came, they were so soft. They were not violent," said Nevnine Onyango, who was present when the officers arrived, accusing her husband of insulting their "boss". "So that is what gave me even more confidence."

The next morning, a family member called with the news that Ojwang, the father of their three-year-old son, was dead.

In the week since, the blogger's death has become a lightning rod in a nation just one year removed from mass youth-led protests that were fuelled, in part, by disgust at pervasive police violence.

Hundreds protested in the capital Nairobi this week, with vehicles set ablaze and the police firing teargas. Demonstrators cited Ojwang's death as evidence that nothing had changed one year after more than 60 people were killed in demonstrations initially sparked by proposed tax hikes.

Ojwang was arrested in Homa Bay, in western Kenya, as part of an investigation triggered by a formal complaint from the deputy chief of the national police force, Eliud Lagat, according to the Independent Policing Oversight Authority, Kenya's government-funded police watchdog.

Lagat had stated he had been the target of alleged false and malicious information published on X, IPOA said.

Kenya's police chief initially implied that Ojwang had died by suicide but later apologised after an autopsy found that his wounds - including a head injury, neck compression and soft tissue damage - pointed to assault as the cause of death.

President William Ruto said on Wednesday that Ojwang had died "at the hands of the police", which he said was "heartbreaking and unacceptable".

Three people have so far been arrested in the case: the policeman in charge of the police station in Nairobi where Ojwang was found dead, a police constable and a closed-circuit television technician at the station.

Reuters was not able to reach Lagat for comment, and a police spokesperson did not respond to a request for comment. In the past, the police have called examples of abuse isolated incidents.

SUPPOSED TO PROTECT, NOT HARM

It is not clear what Ojwang posted that got the attention of the police. His social media accounts no longer appear to be active.

According to IPOA, which is investigating his death, Lagat's complaint triggered a probe that led to the arrest of another blogger.

Interrogations of that blogger identified Ojwang as a person of interest, IPOA said.

And so, last Saturday at lunchtime, police officers arrived at Ojwang's house on motorcycles and told him "there are some remarks that he had made about their boss, that the boss is corrupt", his wife Onyango said. They did not identify their boss.

They first took Ojwang to the local police station before telling his family they would transfer him to Nairobi, nearly 300 km (185 miles) away, she said.

She last heard from him at around 9 p.m. (1800 GMT) the Saturday of his arrest when he called her from Nairobi's Central Police Station. She said he sounded worried and asked if she would be able to come to Nairobi.

Onyango is now hoping for answers - and accountability - from IPOA's investigation.

"We always see these things on television, and it actually reached my door," she said of police abuses. "These people are supposed to protect us. They're not supposed to harm us."

(Reporting by Aaron Ross; Editing by Joe Bavier)