Maureen Wanjiku and her six-month-old son were found in their apartment with serious injuries by police, who rushed to the scene after receiving a 9-1-1 call.
Ms Wanjiku suffered multiple stab wounds and was pronounced dead at the scene while the infant was taken to a local hospital but succumbed to his injuries.
Anaheim police swung into action after receiving reports from eyewitnesses that the woman’s boyfriend, who has been identified as Kwame Carpenter, 24, was seen fleeing from the scene.
They quickly circulated his photo and that of a vehicle he was believed to be driving.
They have since labelled Mr Carpenter as a person of interest.
POSING FOR PHOTOS
On his Facebook page, Mr Carpenter is seen posing for photos with the infant but not with Ms Wanjiku.
The police towed two vehicles found outside the apartment block where the couple are believed to have been living.
Kenyans living in the Anaheim area gathered at the scene of the killings and others at the Anaheim Police Department.
“Our family is devastated and has been hit hard by this tragedy,” said Mr Isaac Kariuki, an uncle to Ms Wanjiku, speaking to nation.co.ke from Maryland.
Mr Kariuki is also the proprietor of Diasporamessenger.com, a Kenyan news website in the US.
In other news, a 24-year-old Kenyan man drowned in a pool in Orlando, Florida over the weekend.
Anthony Lemaiyan Kosen, who drowned in a pool at home on Saturday, arrived in the United States three weeks ago after winning the Diversity Visa Lottery, popularly known as the Green Card.
Lemeiyan’s body was found floating in the pool when his host family returned from visiting a Kenyan family living in the same area.
His body is expected to be transported back to Kenya for burial.