The incident was reported just after 2 p.m.
Upon arrival by Dublin police, an adult male victim was located with a gunshot wound to his head. The victim was pronounced deceased at the scene.
INTERACTIVE: Take a look at the ABC7 Neighborhood Safety Tracker
Residents were blocked from getting into the complex during the search.
Nearby Dougherty Elementary School was also locked down while police searched for the suspect. The lockdown was lifted just before 4 p.m.
Police said they were still searching for the suspect. The victim's identity is being held.
Sandra Cardenas has lived at the complex for three years.
MORE: 2 dead, 2 injured after argument leads to shooting in East Oakland, police say
"I was just shocked, because we are normally a quiet community and living close to an elementary school. I never really thought we'd have that incident happen here," Cardenas said.
According to city data, there's been less than a handful of murders reported since 2014: two in 2020 and two in 2022.
"I'd say everybody is getting home from work right now and not expecting to see police as you come into the complex and definitely getting the message from the apartment complex a fatality happened here during the day is kind of mind blowing," Cardenas said.
Stay with ABC7 News for the latest details on this developing story.