Security has arrested former Police Special Operations commander Nixon Agasirwe in connection to the murder of state prosecutor, Joan Kagezi.
Kagezi was killed by unknown assailants in 2015 as she returned home in Kiwatule, a Kampala suburb.
She was gunned down in her vehicle before her children as she stopped to buy fruits on the roadside.
At the time of her killing, Kagezi was prosecuting suspects involved in the infamous 2010 twin bombing case at the High Court of Kampala.
On Monday, Daniel Kisekka, 47, pleaded guilty to the charges of murder under the plea bargain arrangement , a system that allows an accused to own up to committing the offence in exchange for a lighter sentence.
He later turned a state witness, and during his testimony, Kisekka said the mission to kill Kagezi was brought by a man named Nixon who was by then driving a government vehicle.
On Thursday, sources said Agasiirwe had been arrested by the Flying Squad.
He was previously linked to a number of atrocities against members of the public.