The Fullerton (Calif.) Police chief who has been fending off questions about whether six of his officers used excessive force on a homeless, mentally ill man has been placed on medical leave.

Following the decision by Chief Michael Sellers' doctor to place the chief on medical leave, City Manager Joe Felz named Capt. Kevin Hamilton as interim chief.

Hamilton, who took over the department Wednesday, has been a Fullerton PD officer since 1979. The 53-year-old Hamilton has worked in virtually all divisions of the department, including patrol, traffic investigation, narcotics, SWAT, and the detective bureau. He was promoted to captain in 2010.

"We wish Chief Sellers well, and are appreciative of his efforts in behalf of the city," said Felz in a statement. "We are very grateful that we can call on Kevin Hamilton for his services. I'm confident he will do a good job."

Hamilton takes over as the department is dealing with the fallout from the rough arrest of Kelly Thomas, 37, by six officers in early July. The six officers involved in the fatal beating of Thomas have been suspended and investigations have been launched by the department, Orange County District Attorney's Office and FBI.

As acting chief, Hamilton said his "top priority and responsibility is to police the city," he said in a statement. "That's our job and I will make sure we do it."

He added, "We also have very important issues we have to deal with in light of the Kelly Thomas incident, and we will work with investigators from the District Attorney's Office and the FBI, who are looking into the incident."

Hamilton said he is also looking forward to working with the independent consultant selected to conduct an independent administrative inquiry and review of policies and procedures at the department. Felz will recommend to the City Council that the city hire Michael Gennaco, a consultant who works with law enforcement agencies across the nation.

In addition to his independent consultant work, Gennaco is chief attorney for the Los Angeles County Office of Independent Review (OIR), a civilian oversight committee created by the Los Angeles County supervisors to monitor the county's sheriff's department.

Hamilton was born and raised in Norwalk and holds a bachelor's degree in occupational studies from California State University, Long Beach.