A Delhi Police head constable was arrested yesterday for the murder of his former colleague, two years after he allegedly choked her to death and threw her body in a canal. Behind the arrest of Surendra Rana (42) was a long wait and relentless pursuit of justice by the victim Mona Yadav's family. Recounting the harrowing journey to find the truth about her missing sister and the struggle to get her justice, Mona's elder sister broke down several times in the office of a senior police officer. As she spoke of a family's dreams for its daughter and how they turned to ashes, those present in the office, including some journalists, were left speechless. She fainted several times as she spoke.