Ray Kelly tells the San Francisco Chronicle that Ujiri tried to push past a deputy who then asked for his credential.
The Sheriff's Office labeled the incident battery on an officer, classified as a misdemeanor, and will be investigating with the Oakland Police Department.
Footage shows the aftermath of a situation during which Ujiri is being separated from a law enforcement officer.
Thursday's alleged incident occurred in the moments after the Raptors' NBA championship victory on the floor of Oracle Arena.
NBC Sports Washington previously reported the Wizards' interest in Ujiri and Thursday night, ESPN reported the team was planning an offer of almost $10 million a year. Last July, around the time the team completed a trade for Kawhi Leonard, Ujiri was in Kenya, joined by former president Barack Obama, as Giants of Africa opened a custom court on the campus of Sauti Kuu Foundation Sports.
Kelly added: "It's not like we were going to chase him down". Ujiri is accused of twice shoving an officer and striking him in the face after he was blocked from entering the court because he didn't display his game credential.
According to NBC Bay Area, the Alameda County Sheriff's Office said that the deputy was pushed and struck in the face.
"There is a credentialling policy that the National Basketball Association has in place".
The Washington Wizards are preparing to offer Toronto Raptors president Masai Ujiri a monumental offer that could include an annual salary close to $10 million and an opportunity for ownership equity, Adrian Wojnarowski of ESPN reports.