By Sarah Parvini, Veronica Rocha, Richard Winton and and Joe Mozingo

She called police because her brother was "not acting like himself."

He was walking in and out of traffic in the scorching afternoon sun. Three times, she said, she called 911, telling dispatchers he was sick and needed help.

El Cajon police were dispatched on a 5150 call, a request for an involuntary psychiatric hold. Officers spotted Alfred Okwera Olango behind a downtown restaurant in a parking lot backed by low-slung apartment buildings. Moments later, police opened fire on the 38-year-old African American man, mortally wounding him.

The shooting sparked protests in the San Diego suburb and became a new flashpoint in the long-running debate about deadly encounters between police and people with mental illnesses.

Law enforcement agencies have been focusing training in recent years on de-escalating confrontations between officers and the mentally ill as a way of reducing violence.

But the shooting Tuesday in El Cajon underscores both the challenges officers face when making split-second decisions and what critics say are inadequate policies and training on how to end these types of interactions without resorting to violence.

El Cajon Police Chief Jeff Davis said Olango ignored multiple orders from an officer and "concealed his hand in his pants pockets." He paced back and forth as two officers talked to him, then "rapidly drew an object from his front pants pockets, placed both hands together on it and extended it rapidly toward [one] officer, taking what appeared to be a shooting stance," the chief said.

That officer opened fire, while the other officer deployed his Taser gun. Davis declined to say the number of shots that were fired. No firearm was found at the scene, but police said they recovered a vape smoking device that officials believe he was holding in his hand.

The department did not release video of the incident, but did post a photo showing Olango pointing at an officer's face as if he had a gun.

Police said the officers did not have body or dash cameras but recovered one cellphone video of the shooting from an eyewitness.

Bystanders posted video of Olango's sister reacting to the shooting, at one point crying: "You killed my brother!"

"Don't you guys have a crisis communication team to talk to somebody mentally sick?" she asked an officer.

Some critics of the way police deal with the mentally ill joined calls from local community activists for the police to release the full video, saying it would help determine whether the officers acted properly.

"Police departments are not doing enough with the mentally ill. They talk about training and training for officers. But what about accountability?" said activist Ron Thomas, a former Orange County sheriff's deputy whose mentally ill son Kelly was killed by Fullerton police in 2011. "Departments aren't holding officers accountable when they harm the mentally ill."

A Facebook page for Alfred Olango identifies him as a head cook at a Hooters restaurant who is originally from Uganda. It says he went to San Diego High School and studied at San Diego Mesa College.

Within hours of the killing, protests erupted in the city, and they resumed on Wednesday.

At a news conference Wednesday morning, Agnes Hassan, a relative, said she and Olango had been in a refugee camp together before coming to the U.S. to make a better life for themselves and their children.

"We suffered too much with the war in Africa.... We come here, to suffer again," she said.

Hassan said she was heartbroken.

"What happened yesterday, it wasn't right," she said.

Some community activists said they were concerned that Olango's race -- as well as his mental condition -- played a role in the officers' actions.

Bishop Cornelius Bowser, a gang interventionist at Pastor of Charity Apostolic Church, said residents don't trust the department, that relations between the black community and police have "been ruined already."

"We don't want to see a still picture," he said. "We want to see the whole story."

El Cajon police said they have not released the whole video because San Diego law enforcement protocol states that officer-involved shooting video -- whether from witnesses or police body-worn cameras -- should not be released until the district attorney has reviewed it. It's unclear when that will occur.

The city's mayor, Bill Wells, said Wednesday that the FBI had joined the investigation of the shooting, and he urged calm and understanding in the community.

"I saw a man who was distraught, a man who was acting out like he was in great pain. I saw him get gunned down and killed. If it was my son, I would be devastated," he said. "The most important thing to take away ... today is a tragedy occurred in El Cajon yesterday. We lost a life. Nobody wants to see the loss of a life."

The El Cajon shooting comes amid ongoing national anguish over police shootings of blacks. Last week, Charlotte, N.C., was rocked by days of protests after police fatally shot 43-year-old Keith Lamont Scott. Police say Scott was armed, but the video released of the killing does not clearly show his hands, doing little to quell the unrest.

Experts on police procedure said they needed more information to say whether the shooting was justified.

Ed Obayashi, a Plumas County, Calif., sheriff's deputy and legal advisor, said that even training officers to de-escalate interactions with the mentally ill may not have helped in this case.

"When those hands come up in a shooting stance, the officer wouldn't have time to assess whether what is in the hands is a gun," Obayashi said. "Almost immediately, the officer sees the hands flash up into a shooting stance, he must react. A second will be too late if it's a firearm."

He said the situation appeared to unfold quickly, "so there was no time to call for a mental health crisis team."

Former LAPD Capt. Greg Meyer, who oversaw mental health training and testifies in use-of-force trials, agreed, saying the officers didn't have time to see if the Taser alone would have subdued him.

"These things happen in split seconds," he said.

The Los Angeles Police Department, among many other agencies, has been beefing up training for how officers deal with mentally ill people, after a series of controversial shootings.

Sam Cochran, a retired major with the Memphis police who pioneered mental health policing in the U.S., said the key to dealing with the mentally ill is to calm the situation. The officers want to begin a conversation to reduce tensions, to de-escalate the situation. But he said a man with his hands in his pockets, refusing to cooperate, can be tough. "Every situation is different."

A 2015 Police Executive Research Forum survey of 281 police agencies found the average young officer received 58 hours of firearms training and 49 hours of defensive tactical training but only eight hours of de-escalation training.

About 100 protesters gathered at the El Cajon police headquarters on Wednesday morning, calling for an end to killings of unarmed black men across the country, invoking the names of Trayvon Martin, Michael Brown and Freddie Gray.

"Now, it's finally hitting home," said JJ Balancier, 27.

Abu Djinko stood under the shade of a tree, just listening. "This is nothing new to me," Djinko said. The 20-year-old student said his cousin was killed by police after fighting with another man last year.

"There's a clear fear of my people, for some reason," Djinko said. "This man was unarmed and mentally ill. What compels you to kill when you're supposed to serve and protect?"

Parvini and Hernandez reported from El Cajon; Mozingo and Winton from Los Angeles. Times staff writer Veronica Rocha and Pauline Repard and Lyndsay Winkley of the San Diego Union Tribune contributed to this report.

(c)2016 the Los Angeles Times