Korane was picked up Tuesday morning alongside three other suspects whom police believe were involved.
Police officers, who are said to have camped outside the governor’s house in Kileleshwa overnight, pounced on him when he came out at 5am.
The officers went for Mr Korane after three other suspects in remand linked him to the attack.
Police say they are all being investigated after evidence showed that they planned to kill Idriss Mukhtar who was shot in the head outside a hotel in Nairobi’s Kileleshwa.
Mr Mkutar was shot in the head by a three-man gang outside a hotel in the capital.
Police investigations revealed that the gang trailed the victim to his car and shot him at close range before escaping without stealing anything from him.
His family said Mukhtar had complained of threats to his life. He shared his statement in which he named possible suspects behind the threats with his lawyers. Mukhtar had been sacked by the former Garissa administration and moved to court where he was awarded Sh50 million for wrongful sacking.
Mukhtar is in a critical condition in Nairobi Hospital.
The probe on the shooting was accelerated by a directive from the Director of Public Prosecutions Noordin Haji who demanded the file within a week