When an officer is fired by the police review board, the police union can appeal the decision by going to an arbitrator. That person then acts as a judge, hears both sides of the case and decides whether the officer can return to duty. Two weeks ago, arbitrator David Stiteler overturned the police department's termination of Roche and ordered him reinstated with back pay.
In 2011, Officer Hector Jimenez was also ordered back on the job by an arbitrator after being fired for shooting an unarmed suspect in the back.
This is not an uncommon problem, says Professor David Harris, an expert in police misconduct at the University of Pittsburgh School of Law.
"I hear this complaint almost more often than any other from police leaders. 'I fired the guy, he did this, I fired him and I got him back. I can't get rid of these officers,' " Harris said.
Sometimes the city does not build strong enough cases at arbitration hearings.
"If the city that is involved in these things does not put enough evidence in front of the arbitrator, the arbitrator has to come out for the police officer," Harris said.
It's rare that an arbitration decision can be overturned. But Oakland is in a unusual situation. Since 2003 the Oakland Police Department has been under court order to reform after the Riders police brutality case, in which four officers were accused of beating and framing suspects in West Oakland.
Henderson ordered court-appointed federal monitor Robert Warshaw to investigate why police review board decisions are being frequently overturned. The judge also questioned whether the city is providing adequate counsel and bringing the appropriate witnesses.
Judge Orders Investigation into Reinstated Oakland Police by KQED News
Tara Siler contributed to this report.