Businessman Chris Obure will be charged with the killing of fellow businessman Kevin Omwenga.
Justice Ngugi noted that the only court that can properly receive and unravel the many threads and permutations of a murder charge is the court which will hear the evidence.
“The applicant cannot purport to instruct the office of the DPP on whether to charge him or have him appear as a witness,” she explained.
On Monday, Obure had made an application to be a witness in the murder trial, saying he had been cooperating with detectives.
The court also heard that the CCTV footage that placed the businessman’s bodyguard Robert Bodo in the heart of the matter had been tampered with.