Twin Cities attorney Don Lewis, left, will join the office of Ramsey County Attorney John Choi, right, in the inquiry into the death of Philando Castile. (The Minnesota Star Tribune)

The Philando Castile case keeps forcing Minnesota to grapple with deep questions about racism, justice and the credibility of the criminal justice system — this time with the call by some in the community for an independent prosecutor.

The push for such a person, who would operate outside of the Ramsey County attorney's office, is understandable, but in this case unjustified. Independent prosecutors can and should be an option when there is reason to believe an elected county attorney's impartiality is compromised in some way, making a fair outcome unlikely. There is no such indication here.

The decision to indict a St. Anthony police officer for shooting Castile during a Falcon Heights traffic stop rests with the Ramsey County attorney, who is no son of white privilege. John Choi came here as a child immigrant from South Korea, lived in low-income housing, and rose to become a national leader on sex trafficking and domestic violence. He has publicly acknowledged racial disparities in the criminal justice system and pledged to make addressing them a priority.

Neither does Choi have the kind of extensive relationships with the St. Anthony Police Department that might affect his judgment. The department is part of Hennepin County, but provides contract services for Falcon Heights, mostly involving low-level traffic tickets. Choi went the extra measure, however, reaching outside of his staff to a formidable and well-respected figure in the legal community: attorney Don Lewis.

Lewis has a law degree from Harvard and 30 years of experience in private and public practice. He is a former assistant U.S. attorney for Minnesota and a former dean of the Hamline Law School, co-founder of the Minnesota Association of Black Lawyers, and he was twice named one of the most influential black attorneys in the nation. Raised in St. Paul's Rondo neighborhood, he got his start working for the U.S. Justice Department's civil rights division, where he investigated segregation in colleges and universities in the South. It's hard to imagine someone more qualified to apply a rigorous standard or scrupulous eye to the case at hand.

The Castile family's own lawyer, Glenda Hatchett, said in a letter to Choi that "Attorney Lewis has years of legal experience in public service, as well as private practice, and we welcome his involvement in this investigation. This appointment is a step in the right direction and we trust that justice will be served."

Choi deserves praise for seeking out such a qualified person, just as Lewis should be commended for taking on such a thankless but necessary job. It would be far easier to hand it off to a third party, who would not be accountable to the public.

Less helpful was former St. Paul Mayor Jim Scheibel's recent call for an independent prosecutor, in which he also noted that he had "the utmost confidence in Don Lewis" and that his call should not reflect on Choi. But you can't have it both ways. Either Choi and Lewis fall short, necessitating a neutral outside figure, or you have confidence in their abilities to produce a fair result. Otherwise, the message is that the only way to instill confidence is to go outside the system of democratically elected officials and anyone who may work for them.

In this instance, Minnesota is fortunate to have two investigators who have earned trust over time, will be accountable to the public and deserve to be allowed to do their jobs.