In San Diego, at the La Jolla Crossroads apartments, where a deadly shooting took place on Sunday.(AP Photo)

The pool party was in full swing when a lone man reclining in a lounge chair with a blank expression pulled a gun from his waistband and began shooting.

As bodies fell on the pool deck and people ran for their lives, the gunman despondent over a recent breakup dialled his ex-girlfriend so she could listen as he continued firing at strangers.

Although Peter Selis was white and all but one of the victims were black and Latino, Chief Shelley Zimmerman said Monday there was “zero indication” race was a motive.

Instead, the attack that killed one woman and injured six other party-goers seemed to be driven by a recent split-up with the woman he called after he shot his first two victims.

“It is apparent that Selis wanted his ex-girlfriend to listen in as he carried out his rampage,” Zimmerman said. “These victims were just in his vicinity when he committed this terrible tragedy.”

Selis, 49, was gunned down in a shootout Sunday with police in the upscale apartment complex where people screamed in terror as gunshots echoed between the towers.

Less than an hour earlier, Selis had stood out from the crowd of about 35 as he sat alone in the pool area of the massive La Jolla Crossroads apartment complex, where he lived on Judicial Drive.

As children splashed, a family soaked in a hot tub and others ate chips and hot dogs, Selis sat by the pool gate wearing a heavy black jacket on a hot day, said Demetrius Griffin, a guest at the party.

Crews clean up blood on the ground at the La Jolla Crossroads apartments (AP Photo)

The shooting began after the man celebrating his 50th birthday approached Selis. Griffin assumed his friend, who was always welcoming, invited the man to join the fun.

Instead, Selis pulled a gun from his waistband, shot the party host twice in the torso and then opened fire on the party, Griffin said.

“It was very eerie, to say the least,” Griffin said. “He didn’t stand up. He didn’t say anything. He just opened fire.”

Griffin briefly froze and then dropped to the ground as six rounds sent people scattering and dropped others on the pool deck.

Selis called his ex-girlfriend during the shooting and immediately told her that he had shot two people, the police were arriving and then “made some reference to ‘shooting it out’ or something along those lines,” assistant police chief Brian Ahearn said. The woman heard two more gunshots before the line went dead, Ahearn said.

One victim, 34-year-old Thomas Blea, said he was grateful to a security guard at the apartment complex who hustled him and two other victims quickly to safety.

“That guy saved us a lot of time. Getting us to the fire department in a safe zone,” said Blea as he sat with his leg bandaged in a wheelchair outside the hospital. The guard’s name has not been released.

Selis, a father who worked as a mechanic at a Ford dealership, had been distraught and depressed after a breakup just days before, though family and friends interviewed by police had no hint of any sinister plot.

He filed for federal bankruptcy protection in October 2015, listing $14,000 in assets and $108,000 in liabilities, according to court records.

Selis shot three black women, two black men, a Latino man and a white woman, police said.

Demetrius Griffin was a guest in the poolside birthday party in which a gunman opened fire. (AP Photo)

Six of the shooting victims were expected to survive, Zimmerman said. Another man was taken to the hospital after he broke his arm running away.

None of the victims was identified. Efforts to reach his ex-girlfriend were unsuccessful.

Investigators have not found any writings or evidence from internet searches that Selis had planned the shootings, Ahearn said.

“There was nothing obvious or public that this was his intention,” he said.

Griffin, who helped carry a woman shot in the legs to safety, woke up Monday in a panic thinking he was still at the pool.

“I was shaking. I started crying,” he said. “My eyes got really, really big as if they were going to pop out of my head and I kind of rolled over off the couch, onto the floor as if the gunman were still active.”