President William Ruto on Saturday appointed Amin Mohammed Ibrahim as the new Directorate of Criminal Investigations (DCI) boss.
Mr Amin, 58, replaces George Kinoti who resigned as DCI boss last month.
Amin was picked from a list of four seasoned detectives whose names were forwarded to the president by the National Police Service Commission on Friday.
The other three names were DCI head of planning Nicholas Kamwende, DCI head of reforms Eliud Langat and principal deputy to the Inspector General Nyale Munga.
In a gazette notice published on Friday, President Ruto announced that Amin was the new DCI chief, ending a period of intense lobbying for the position.
Amin has both professional and personal relationship with Ruto, and have known each other for over 15 years.
Yesterday, Amin told The Sunday Standard on phone that he was grateful for the appointment.
"I am more than happy," Amin said.
Those who understand the relationship between the new DCI head and his boss say the two have enjoyed a good working relationship since 2006 when Amin was first posted to Rift Valley where he served as the regional DCI boss.
In 2007, Amin and Ruto, who was then the Eldoret North MP, would occasionally cross paths following post-election skirmishes that followed the disputed presidential election.
Amin was in the middle of the post-election violence investigations that led to the death of hundreds of people and left over 6,000 others internally displaced.
He would eventually end up at the International Criminal Court (ICC) in the Hague where he gave testimony in the defence of former Police Commissioner Maj General Hussein Ali, who was one of the top government officials charged at the court.
Other suspects in the ICC cases included President Ruto, former President Uhuru Kenyatta, former head of Public Service Francis Muthaura and radio journalist Joshua Sang.
Former Minister Henry Koskei was also in the group of those charged at the court. The cases were later dropped by the court in 2016.
Amin gained prominence again recently after he was tasked with investigating the disappearance of three Indian nationals and a taxi driver who went missing in controversial circumstances in Nairobi during the election period.
The matter was initially being investigated by Langata DCI officers before it was moved to the National Police Internal Affairs Unit (IAU), which he has been heading.
This was after it emerged that security officers could have been involved in the disappearance of the men.
More than 160 people had expressed interest in succeeding Kinoti, but only 10 were shortlisted by the National Police Service Commission.
Kinoti served at the helm of the investigative agency between January 2018 and September 2022.
He has since landed a job with the Public Service Commission.