The five were involved in the murder of a woman of Govindpuram area here after she had filed a case of rape against Tarun, son of the sub-inspector Bacchu Singh, police said.
"Police has arrested Bacchu Singh, his son Tarun, constable Vinesh, Amarpal and his wife Rashmi," a police officer said, adding that another constable and an accomplice were on the run and would be nabbed soon.
Tarun had been in a relationship with the woman and had promised to marry her, but later refused to do so. On March 1 last year, the woman registered a case against him, which included rape charge, SP (city), Shiv Hari Meena said.
On December 2 last year, the woman's parents registered a complaint against Tarun and Bacchu after she had gone missing, another police officer said.
Amarpal, his wife Rashmi, who is also a journalist, and an accomplice Ritesh had strangled the woman to death on November 30 last year and thrown her body in a canal in Aligarh district, the officer said.