Officers got to the scene and found a man and a woman dead with single-shot head wounds in a parking lot on 11517 Los Nietos Road.
The man and woman appeared to be Hispanic and in their 30s, and their names have not yet been officially released.
"It's a horrible way to die, I don't know, but sometimes when we live life on the streets, it catches up," said Cathy, a friend of the female victim.
She said that one of the victims was her friend, Celest, a 31-year-old mother. Cathy added that the other victim was Celest's former boyfriend.
Police have yet to uncover any motive behind this cold and calculating crime.
"No matter what we do in our life, we're still human, and nobody deserves to die like that, nobody does," said Cathy.
Anyone with information is urged to call the Whittier Police Department at (562) 945-8250.