The man stabbed his girlfriend seven times using a kitchen knife killing her on the spot.
Starehe Police Boss Bernard Nyakwaka says the 27-year-old man stabbed the woman and then walked to the rooftop of their house where he swallowed poison.
Speaking to Capital FM News, Nyakwaka said the man’s body was later found in the rooftop while the 26-year-old woman’s body was in their bedroom in a pool of blood.
“We are questioning the relatives about the occurrence…their relationship was not stable. It could have happened out of a love triangle,” he said.
Family quarrels within the city are frequent, and they either lead to death of both or one partner.
Just two weeks ago, a woman killed her boyfriend by stabbing him 22 times in their house in Buruburu, Nairobi after a quarrel.
The woman has so far been charged with murder.
Elsewhere, police are holding a woman after she allegedly killed and dumped her infant in a dustbin in Kibera slums.
The woman had given birth to the infant at a clinic in the area when she allegedly walked out and killed it.
Residents discovered the infant in a paper bag and alerted police who traced and arrested her.