The Independent Policing Oversight Authority (Ipoa) is investigating the shooting of a suspect facing robbery with violence charges after the suspect's lawyer accused the police of extrajudicial killing.
Lawyer Cliff Ombeta shared a clip on Twitter that appears to capture three police officers confronting a man and before a gunshot is heard.
Mr Ombeta claimed detectives from the Directorate of Criminal Investigations (DCI) pulled Vincent Wycliffe Oduor, who was out on bond, from a barber shop and shot him dead even though he was unarmed.
On Wednesday, DCI issued a statement on Twitter saying police officers had gunned down a key suspect of the Sh72 million ATM heist in a shootout in Kayole on Tuesday evening.
DCI said the suspect was in the company of two others who escaped on a motorcycle after they were confronted by police.
"Armed with pistols and riding on a motorbike, the three were robbing members of public at the said location," the DCI said.
But Mr Ombeta in a series of tweets said there was no attempted robbery and that his client was not armed as the police claimed.
"This was an execution. Everything else you are saying is a lie. There was no 'fierce shootout', no reports of robberies, no muggings within that jurisdiction. This one, you will not cover up. I will not let you.
You know why you executed him, Do do I," Mr Ombeta said on Twitter.
In the video, whose authenticity the Nation could not independently confirm, the man is pushed and pulled as he pleads with the three men and tries to resist being dragged.
The clip ends with the sound of a single gunshot.
IPOA will establish whether there was use of excessive force in the shooting of the suspect and forward their recommendations to the Office of the Director of Public Prosecution and the National Police Service's Internal Affairs Unit for action.
The suspect, commonly known as Vinii, was charged in court last year and released on Sh500,000 bond.
After the robbery, Administration Police officers Florence Wanjiru Karuku, Simon Gichuhi Karuku and his wife Caroline Njeri Waithira were arrested.
A KDF officer, Eunice Wangari Karuku, who was based at the Kahawa Barracks, was also arrested and interrogated.
Several other security guards working with the G4S Company were arrested in different parts of the country some money recovered.