Chania, who unsuccessfully vied for the Kiambu Woman Representative seat in August, was arrested on Friday.
Three other suspects are also set to appear before the Kiambu court as police are expected to ask for more time to investigate.
The matter has been taken over by detectives from the Directorate of Criminal Investigations (DCI).
"The matter has been taking different dimensions. Forensic experts ... have taken over the investigations," a detective said.
Chania has since been transferred from Kiambu to Nairobi as police hunt for a farmhand to record a statement over the incident. A detective privy to the investigations told The Standard a government pathologist is set to examine Mwangi's body this week to establish the cause of death.
Preliminary investigations by DCI sleuths show Mwangi returned to Kenya on September 13, 2022. Police say his murder may be linked to an alleged romantic relationship he had with a school secretary.
Detectives at the weekend shifted their focus to trace the whereabouts of the couple's worker who also disappeared around the time Mwangi was found dead.
Detectives investigating the murder believe the farmhand, Maurice Mbugua, will shed light on the case.
Simultaneously, the detectives are still investigating the love triangle angle, with the woman recording a statement.
On Friday, detectives went to the murder scene in Mang'u and recovered some of the weapons used to murder the engineer.
According to the DCI, the murder weapons were discovered in the master bedroom.
"The sleuths also discovered blood-soaked bed sheets, curtains, and clothing hidden in a locked room adjacent to the master bedroom," the DCI said in a statement.
Police believe the victim was murdered after being hit with a blunt object inside his own home, and his body was dumped 20km away.
The body is thought to have been disfigured with acid. Police are piecing together evidence to show how the murder, which they believe was premeditated, was carried out.
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