According to the postmortem results released on Friday, January 21, Esther Wambui died of strangulation.
The pathologist Dr Simon Omuok, who conducted the autopsy at City Mortuary also indicated that the deceased was hit in the head with a blunt object.
Police took samples to conduct further investigations into the death of the 18-year-old who they suspect might have been sexually abused before being killed.
Her husband, Joseph Ngigi, and her father, Samuel Mbugua, were present during the autopsy. Her husband is also a person of interest in the case.
Detectives investigating the matter retrieved CCTV from her workplace which showed that she left for home at 8.30pm on Sunday, January 9.
Her husband told officers that he usually escorted Wambui to work due to insecurity in the area they lived in and he would also pick her up at the end of her shift.
Ngigi told investigators that he chaperoned Wambui to work at 5.40am on Sunday, January 16, given that it was dark and midway through, he returned home since the day had already broken.
The CCTV footage showed Wambui leaving work for home at 8.30 pm on that Sunday but Ngigi did not pick her up on that day as is the norm.
Wambui worked as a waitress at a hotel at a fuel station in Ruiru.
Preliminary investigations had suggested that Wambui had been killed elsewhere and the body dumped outside the GSU camp.
“It was reported by members of the public that there was a dead body in a briefcase which had been dumped near the service lane along the perimeter wall of the Recce Company Camp at Toll area M/R BJ755775 about 4km south of the station.
“Police officers visited the scene and confirmed that there was a body of an unknown African female adult in her early twenties who had been stashed in a nylon sack and put in a black suitcase with the hands tied at the back and both legs as well tied with manila ropes,” a police report read.