Investigators are also continuing to probe a second home invasion robbery on Friday in which a 77-year-old woman was killed, police said at a morning news conference at police headquarters.
Four of the five people in custody were arrested in connection with a home invasion that happened the morning of Jan. 28 in the 4100 block of Laguna Avenue in Oakland's Lincoln Highlands neighborhood.
In that case, an 81-year-old woman was shot by the intruders but survived.
Police have not yet released the suspects' names but said they are an 18-year-old man, a 19-year-old man and two 16-year-old boys. Police Capt. Sharon Williams said all four have a history of thefts, including car break-ins.
Police Chief Sean Whent said investigators are looking into whether the four suspects are also connected to any other recent crimes.
The fifth arrest was related to a homicide that was reported at about 10:50 a.m. Saturday in the 1700 block of 103rd Avenue in East Oakland.
The victim in that case was a 69-year-old woman, and the suspect in custody is a 42-year-old man, Williams said.
Police have not yet released their names, but Williams said it appears they knew each other. Police have remained mum on the details of the killing.
The names of the adult suspects in the two crimes will be released once charges are filed by the Alameda County District Attorney's Office, according to police.
Lt. John Lois said police are still looking for suspects in the fatal home invasion case, which was discovered at about 2:15 p.m. Friday in the 1800 block of 34th Avenue.
Officers arrived to find the victim, 77-year-old Susan Fong, unresponsive. She was pronounced dead at the scene. There were signs of forced entry, police said.
There was also a man in the home who police said today may be a relative of the victim. He is not considered a suspect in the case, Lois said.
Lois said the residents may have been specifically targeted.
Police initially went to the home after another relative asked them to perform a welfare check on the victim.
Whent said the two home invasions are "each distinct; they are not related." Investigations into both crimes are continuing, he said.
Whent said police are working to prevent further such crimes from happening in the city.
"People should feel free to feel safe inside their own homes," he said.
Investigators are offering a reward of up to $10,000 for information leading to an arrest in the 34th Avenue home invasion. Anyone with information on the case is asked to call homicide detectives at (510) 238-3821.