Gates joined the LAPD in 1949 and worked his way up the ranks to become the 49th chief in 1978.
"I wish that people could know just exactly how much he did to help keep America free. He's done so much for special operations committees throughout the free world," said Michael Hillman, former LAPD dep. chief.
As chief, Gates introduced the Special Weapons And Tactics teams (SWAT) to Los Angeles and the world.
"He was definitely a voice for that rank and file, they recognized that. He was also recognized by his peers at the higher levels as a brilliant man," said his brother Steven Gates.
Gates was never short on ideas or shy about sharing them, and he was a magnet for cameras and controversy. When he decided to use an armored battering ram on a suspected crack house, he invited the media along. However, it was the wrong house. A mother and her daughters were inside eating dinner.
The Los Angeles Police Protective League described Gates as a "cop's cop" in a statement on Gates' death.
"He lived his dream and felt blessed to be part of an organization that he cared so much about. Even after retiring, Chief Gates was an active and steadfast supporter of LAPD officers, making frequent appearances to honor officers for their service - from retirements and funerals to ceremonies and charity events, Chief Gates' presence could always be counted on," the LAPPL said in the statement.
Gates is credited with starting Drug Abuse Resistance Education (DARE), which spread through California schools and was adopted as a model in schools across the nation. He also ushered the city through a trouble-free Summer Olympics in 1984.
"No current sitting chief of police gets the same ovation he does. He's a rockstar among law enforcement officers," said Jim Amormino, spokesman for the Orange County Sheriff's Department.
But all the positives were clouded with the taped beating of Rodney King in 1991. Gates was seen as brushing off the beating when he called it an aberration and talked about King's criminal record rather than how the officers acted during the arrest. Later, he modified his remarks and targeted the media.
"It was a terrible thing, everybody agrees with that. But you made it into a spectacular, you made it into something bigger than the Gulf War," he said.
The officers were acquitted after a trial and the city exploded in riots that resulted in nearly 60 fatalities and in millions of dollars in damage.
Gates did much to anger people, with his shoot-from-the-hip style and the paramilitary attitude of the LAPD. He used phrases like "those crummy little politicians," referred to Latinos as lazy, and said black people die because they do not respond to chokeholds the way "normal people" do. Controversy piled on controversy in his final years as chief.
His 43-year career with the LAPD came to an end when he retired in 1992 amid heavy criticism over the department's handling of the Rodney King beating and subsequent L.A. riots.
Current LAPD Chief Charlie Beck served under Gates. Beck paid several visits to Gates, as the former chief was losing his battle to cancer.
"He was a police chief for his time, a very difficult time," said Beck. "His tenure had great impact for the city of Los Angeles both positive and negative. He will be a person that I will miss."
"Everyone is gonna miss me, there's no question about that," Gates said, "whether it's something you miss like a pain in the stomach or whether it's something you miss like something in your heart."
Funeral arrangements have not yet been made.