An officer on Tuesday retraced the signal of a police radio on the day human rights lawyer Willie Kimani and his client were killed.
According to David Chemilil of the Flying Squad, the signal of the pocket radio was first traced to Mavoko law courts on June 23, 2016, at around midday.
Signals retrieved from the Integrated Command Control and Communication System further show the radio moved to Syokimau police post.
At around 7pm, Mr Chemilil said the signal moved towards Mombasa Road before stopping in an open field.
The witness said he sought information relating to all radio phones assigned to police officers at Mlolongo, Syokimau and Athi River stations.
He said he was granted eight radio signals but one was suspicious because it captured a lot of activity and was the one whose initial signal was near Mavoko law courts.
He said the holder of the gadget stayed at the isolated field for more than five hours.
Police suspect it is on this field, on Mombasa Road, that Mr Kimani, his client Josphat Mwenda and their taxi driver, Mr Joseph Muiruri, were tortured to death.
Mr Chemilil said the signal was later traced leaving the area and moving towards the Eastern bypass and later connecting to Thika Super Highway in the night.
The three victims were killed and their bodies stashed in gunny bags and thrown into Athi River near Donyo Sabuk police post.
Four police officers — Fredrick Leliman, Stephen Cheburet, Sylvia Wanjiku and Leonard Maina Mwangi — and police informer Peter Ngugi have denied killing Mr Kimani, Mr Mwenda and Mr Muiruri.
The three were kidnapped after leaving the Mavoko law courts on June 23, 2016.
The hearing resumes on October 30.
Mr Josephat Mwenda had lodged a complaint against an AP officer, alleging the officer shot him and fabricated criminal charges against him.