The DCI is holding a woman suspected to have lured her ex-husband to her house in Mathare before killing him on Monday.
Mary Wanjiku Nduati is detained at Pangani police station after she allegedly stabbed Kelvin Maina twice in the chest killing him.
In an affidavit filed before Makadara law courts where he obtained 14 days custodial orders, corporal Christopher Samoei of Pangani DCI offices said preliminary investigations led to arrest of Nduati and recovery of the murder weapon from her house.
"She was arrested at Muthaiga-Kosovo on March 16 and we are yet to complete investigations," he said.
Samoei said the murder weapon had bloodstains and needed to be taken to the Government Chemist for tests.
He said he required time to take Nduati’s and her former husband's phones to the DCI’s cybercrime unit for analysis as the two are said to have exchanged messages before Maina went to the suspect's house.
The detective said he also needed time to take the suspect for mental assessment and record more witness statements.
Nduati was detained at Pangani police station for 14 days after senior resident magistrate Lewis Gatheru granted orders sought by Samoei.
Edited by R.Wamochie