CHICAGO (CBS) — Mayor Rahm Emanuel on Tuesday backed Police Supt. Garry McCarthy’s decision to promote a top police official who is under scrutiny for his role in the death investigation involving a nephew of former Mayor Richard M. Daley.

McCarthy has named Constantine “Dean” Andrews as the chief of detectives, replacing John Escalante, who was just promoted to first deputy superintendent.

Andrews was implicated in the creation of an allegedly fictious witness statement that helped prevent police and Cook County prosecutors from charging Daley nephew Richard “R.J.” Vanecko in the 2004 death of David Koschman.

Emanuel said the fact Andrews is still under investigation by the City Inspector General’s office does not disqualify him from promotion.

“For the last 18 months, while you were a reporter, he was the head of the Area North. That’s a very big role, and he, like the other promotions across the front, as also the other promotions over the years are based on their professionalism and their capacity; and they’re held accountable for the results ,” the mayor said.

Special prosecutor Daniel Webb – who led the independent probe that led to Vanecko pleading guilty to involuntary manslaughter last year – released a report that revealed a series of messages Andrews and a police sergeant exchanged over personal email, regarding an unidentified witness who claimed Koschman threatened Vanecko before Vanecko hit him.

However, Webb’s report said no evidence was found that any witnesses to the 2004 altercation on Division Street ever made such a statement to police, even though it ended up in the final report used to clear the case without charges against Vanecko in 2011.

G. Flint Taylor, the attorney for Nancy Koschman, David’s mother, says the move sends the wrong message.

“It’s another stain on the department and on this city, to make this promotion at this time,” Taylor said.

City Inspector General Joseph Ferguson is still investigating whether the officers involved in the Koschman case should face disciplinary action.

Emanuel not only supported McCarthy’s decision to promote Andrews, he said he stands behind the police superintendent amid calls from most black aldermen to fire McCarthy.