RELATED: Retired OPD captain shot 6 times during robbery attempt in Oakland
Although he retired from the Oakland Police Department, Joyner has never stopped working to prevent violence in cities from the East Bay to the East Coast.
"He has worked his career to reduce gun violence in Oakland and to be the victim is horrible," said David Muhammad, the executive director for the National Institute for Criminal Justice Reform, a nonprofit based in Oakland.
Just days ago, Muhammad was with Joyner in Indianapolis, working on a crime reduction strategy with city leaders. So to then see surveillance video of Joyner getting shot six times at a West Oakland gas station Thursday afternoon... "It was horrifying."
WATCH: Surveillance video shows struggle before former OPD captain shot at gas station
"My understanding is that Ersie was defending himself," explained Muhammad, who also said, "this is somebody who's incredibly strong, he's a fighter."
Joyner shot one of the gas station suspects, marking the 115th homicide in Oakland this year. It's a number Muhammad says he and Joyner never thought they'd see again.
"We spent the night talking about our heartbreak about Oakland gun violence increasing," he said.
RELATED: Oakland mayor, police chief plead with community as city records 100th homicide
"Every day we have multiple victims come into Highland Hospital where we provide police services, and it's not uncommon over a weekend to see 15-20 people come in with gunshot wounds," said Sgt. Ray Kelly, with the Alameda County Sheriffs Office.
"What we're seeing is these young folks going around and doing these robbery crews, burglary crews, theft crews, all over different cities in the Bay Area."
Kelly says Joyner has been instrumental in reducing gun violence throughout the East Bay, "Anyone that knows Ersie, knows he's an outstanding individual."
Joyner also owns a public safety and security consulting company; he often works on movies and TV shows. On the company's website, Vice President Kamala Harris and former California Governor Jerry Brown both endorse Joyner's crime fighting leadership.