Gee, 64, said he was "humbled and privileged" to have served in the transit agency's police department for 36 years. He will retire Dec. 30.
Gee's leadership was scrutinized after the shooting death of Grant at the hands of former /*BART*/ police officer /*Johannes Mehserle*/ at the Fruitvale station in Oakland on Jan. 1.
Two outside agencies that investigated the BART Police Department in the wake of the shooting criticized the way it was run.
Gee told BART board members today, "Police officers make mistakes. We're human. When they occur they will be investigated fully."
Gee said he's proud that the department is now "more diverse than ever."
BART Director James Fang, who was elected as the board's new president later in the meeting, said Gee's retirement, announced in August, "is very bittersweet because you have been one of our most loyal employees."
Fang also told Gee, "I don't think BART is done with you. There might be something else down the road."
He did not explain the comment and declined to elaborate after the meeting.
Gee said after the meeting that he wasn't sure what Fang was talking about. He said he will still be around in the sense that he will be involved in litigation against BART for Grant's shooting death.
Gee went on medical leave shortly after he announced his retirement in August but he said he recently returned to work.
He said he rarely missed work during his long career at BART but that he took a long medical leave because he was suffering from pneumonia and a staph infection.
Gee said this New Year's Eve will mark the first time he won't be in uniform since he started his career in law enforcement.
BART directors will hold a public hearing at 6 p.m. today to get input from the public on the process for selecting a new police chief.
The transit agency hopes to have a new chief on the job on April