Newly appointed police commanders will find dozens of unresolved matters when they report to office on Monday.
DCI George Kinoti, deputy IG Edward Mbugua (Kenya Police) and Noor Gabow (Administration Police) were appointed in acting capacity on Friday.
Kinoti took over from Ndegwa Muhoro who was sacked as President Uhuru Kenyatta reshuffled teams.
Kinoti's term begins with claims by insiders that top leaders lacked willingness to address key cases.
These include the murder of IEBC's former ICT manager Chris Msando, student Maryanne Wairimu, businessman Jacob Juma and Bobmil Industries owner Bunty Shah.
Msando died with days to the August 8 general election, sparking rumours of foul play since he was in charge of the KIEMS. The commission said the system was safe but NASA leaders demanded thorough investigations with the help of the FBI and Scotland Yard.
Juma was a controversial figure who made many enemies online.
He openly supported Opposition chief Raila Odinga and criticised the
government whenever he felt it had wronged him [Raila].
The businessman, who died aged 42, accused politicians of robbing Kenyans of their peace and considered government officials "enemies of progress".