(CNN) -- The commissioner of the Cambridge, Massachusetts, police department said Thursday he "deeply regrets" the arrest of prominent black Harvard University professor Henry Louis Gates Jr., but stands by the procedures followed by his department. Sgt. Jim Crowley said he has nothing to apologize for in regards to the arrest of Henry Louis Gates Jr. "I believe that Sgt. [James] Crowley acted in a way that is consistent with his training at the department, and consistent with national standards of law enforcement protocol," Commissioner Robert Haas said, referring to the officer who made the July 16 arrest at the professor's home.
@highlight
Officer: "I know what I did was right. I have nothing to apologize for"
@highlight
Sgt. James Crowley said he was exercising caution during professor's arrest
@highlight
Crowley tells newspaper he's not a racist, did CPR on black basketball star
@highlight
Charges were dropped against professor Henry Louis Gates Jr.
@placeholder told CNN Wednesday that although charges had been dropped, he will keep the issue alive.