Hasin (35) and his wife Rina (30) were allegedly killed by Munna Qureshi, who was known to them, at their Ram Ganga Vihar colony residence, police said.
Later, Qureshi also tried to kill self by slitting his veins, Senior Superintendent of Police Satyendravir Singh said.
Prima facie, a dispute arising out of an extra-marital affair was said to be the reason behind the crime, the SSP said.
Qureshi has been admitted to a private hospital in serious condition.