Detectives drawn from the Directorate of Criminal Investigations (DCI) on Thursday evening cordoned off a section of Kaunda Street in Nairobi in a bid to establish where a National Hospital Insurance Fund (NHIF) staffer was shot from.
The officers who included ballistic and forensic experts accessed the roof of one of the buildings and also took footage of CCTV cameras from nearby buildings as they try to resolve the murder which left shock among the deceased's family and the general public.
Detectives have since ruled out the possibility of Waithera having been a victim of an accidental shooting saying her death was a planned assassination.
Investigators ruled that Waithera was shot from one of the buildings in the busy street, with investigations now pursuing the motive behind her assassination.
READ: Puzzle of mysterious shooter behind NHIF staffer's death in Nairobi CBD
Meanwhile, ballistic experts are analyzing the bullet head recovered from her body.
Waithera’s employer NHIF where she worked for a decade and a half has urged members of the public against spreading false information concerning the death of their late employee.
Mary Lilian Waithera’s family speaks
Waithera’s family which is saddened by her demise said she was in her usual mood and didn't relay any fear for her life. On the day of her demise, the family said she left for work normally and did not show any signs that caused worry.
Waithera's husband, Paul Mbogo said his late wife was proactive and on good terms with everyone around her.
“We are very shocked because Mary didn't have any grudge against anyone, we have no apparent reason to say someone was after her," Mbogo said.
Waithera is expected to be laid to rest at her home in Embu County.