According to ARY News correspondent Shahnawaz Shah, the suspect was arrested during the LEAs raid in Gizri area.
The law enforcement agencies have conducted similar raids today in Defence and Clifton areas and rounded up some other suspects. The key suspect has been moved to an undisclosed location for interrogation.
Gunmen on a motorcycle attacked activist Sabeen Mahmud late last Friday in Karachi, as she was leaving her cafe, where she held art exhibitions and talks. She had just hosted a discussion on disappearances in Baluchistan.
Police say their only witness is Mahmud’s mother, who was with her and was wounded. Investigators suspect the killers had a back-up team of two men on a motorcycle and police are poring over CCTV footage.