Upon further search of the home, police said Mancia's family was hiding in the home.
According to KTTV-TV, Mancia was watching fireworks with his wife outside when the suspect entered the apartment. The victim allegedly went inside the home at some point and ran into the intruder. The two were reportedly heard arguing before the suspect beat Mancia.
Mancia's wife did not endure any physical injuries, KTTV reports. She told KNBC-TV that the suspect beat her husband to death with the cane he used to walk.
Mancia allegedly suffered several strokes in the past and was partially paralyzed and sometimes used a wheelchair.
According to KNBC, the suspect is a man who was seen wearing a mask and dark clothes. Police did not specify any other details about the suspect.