The case has also been shifted from the police station in Frere Town to Baloch colony. The case will now be taken care of by Amanullah Khan who is posted at the Baloch colony police station.
The new investigating officer has sent the DNA samples for forensic investigation to a laboratory to determine the causes and circumstances of the murder.
The move comes as a breakthrough was made yesterday when Police arrested the prime suspect Rizwan from the Super Highway area in Karachi.
It is believed that Rizwan had allegedly killed Haleema at her place in Delhi Colony and then left her son at the Edhi Centre claiming that he had founded him abandoned at Do Darya area.
In his initial interrogations, the suspect Rizwan had confessed to the killing and claimed that he has monetary disputes with Haleema after which he killed her and left the child Abdullah at Edhi Centre.
The child Abdullah is still at the Edhi Centre after his biological father and step-brother have been requested to seek his legal custody through the court.