Dr Odour said the killers of the young woman even went ahead to clip off her fingernails in an apparent attempt to tamper with any DNA evidence.
"This person who did all these also tried to clip off the fingernails for reasons which I might not be able to know but for us scientists when we see fingernails clipped off, we think probably the person was trying to hide the evidence so that we are unable to get his DNA from the victim,"
Odour said the only possible explanation for the clipping of the nails was to remove DNA material that may have been there in the event there was a scuffle before Waeni's death.
"I don't know why but in investigations, such nails help in gathering evidence. People fight when dying and DNA evidence can be hidden there," Oduor said.
All is not lost, said Oduor, there were remnants of some fingernails and that samples had been taken for further analysis to help the DCI with investigations.
Odour said Waeni's body was dismembered with the head chopped off and the legs also cut away from the trunk.
The pathologist believes that sharp objects including a hacksaw could have been used in decapitating Waeni's body.
Samples from Waeni's kidney, stomach, vagina and blood had been collected for further toxicological tests.
Waeni's murder has shocked the country after the family revealed the last moments of the fourth-year Jomo Kenyatta University student.
The family in a statement early in the week revealed that the killers had demanded for Sh 500,000 from the family to free Waeni.
In a two-page statement that almost read like a eulogy, the family recounted the last moments of their daughter last Saturday when Waeni left her aunt's home in Syokimau for a meeting that ended in her death.
On Tuesday, a suspect was taken to Kasarani DCI where he was questioned.