Kohat police on Monday said they had arrested one of the main suspects in the Hina Shahnawaz case, along with three alleged accomplices.
District Police Officer Kohat Javed Iqbal said that one of the main perpetrators of the crime, Zulfiqar Ali Bhutto, was arrested in Rawalpindi, while his accomplices were picked up from Kohat.
The other suspect, Mehboob Alam, the victim's cousin, remains at large, but police said they are actively working towards his arrest.
Shahnawaz was gunned down in Kohat's Astarzai area on Feb 6, allegedly by a relative who objected to her working outside the home, police said.
Her relatives attempted to keep the incident hidden, a family member told DawnNews, but a First Information Report was lodged after reports of the murder began circulating on social media.
Iqbal had earlier said the woman, Hina Shahnawaz, had been shot four times.
Soon after, on Feb 13, Mehboob Alam had claimed innocence in a video message posted on social media. He had said that not killed his cousin, but the real culprit was somebody else.
He had also said in the video message that there were several other female members of his family that held jobs, and added that his own sister was a schoolteacher.
He claimed that the victim’s family had tried to trap him for protecting the real murderer.
Shahnawaz had been working at a non-governmental organisation in Islamabad and was earning Rs80,000 a month, which she used to support her widowed mother and sister-in-law after her father and brother passed away, the DPO said.
Alam fled after allegedly killing his cousin, DPO Iqbal said, adding that the police are conducting a search operation in the area to find him.
Pakistan, home to roughly 190 million people, sees thousands of cases of violence against women every year, from rape and acid attacks to sexual assault, kidnappings and so-called "honour killings".
Domestic abuse, and other violence and economic discrimination make Pakistan the world's third-most-dangerous country for women, a 2011 Thomson Reuters Foundation expert poll showed.