Police believe the suspect was lured to his death through a phone call.
In an interview with vernacular media stations Muuga FM, Weru TV, Baite TV, and Baite FM , the governor refuted claims that Muthiani visited her official residence.
Mwangaza said the official residence located in Milimani near Meru town is under CCTV surveillance and police are yet to request for the footage.
She accused her political opponents of using the blogger's death to gain political mileage.
"The security agencies are conducting the investigations and I believe 'Sniper' will get justice," she said.
"The official residence of the governor has numerous CCTV cameras but nobody has requested the footage," she added.
Further, Mwangaza said she does not host meetings at night, save for when she hosted an MCA and an activist.
The governor revealed that the MCA visited her residence to seek reconciliation after her second impeachment.
She said the investigators should be left to do their job and decried attempts to politicise the probe into the blogger's murder .
"Leaders should avoid politicising a death because there is a grieving family. It is unfortunate people try to gain political mileage as the family grieves," she said.
During a requiem service for Muthiani at Kinoru stadium, speakers including Buuri MP Mugambi Rindikiri, 20 MCAs and Meru Assembly Speaker Ayub Bundi, called for the arrest of more suspects behind the blogger's murder.
Muthiani disappeared on December 2 after leaving his home at Kabuitu in Igembe South allegedly to meet a political operative. His widow claimed that the caller had reportedly arranged for meeting between the blogger and the governor.
His body was discovered at a riverbank in the neighbouring Tharaka Nithi county on December 6.
The post-mortem conducted by Government Chief Pathologist Dr Johansen Oduor revealed that Muthiani died due to strangulation.
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