DETROIT  — Former Detroit Mayor Kwame Kilpatrick was convicted Monday of corruption charges, ensuring a return to prison for a man once among the nation’s youngest big-city leaders.

Jurors convicted Kilpatrick of a raft of crimes, including a racketeering conspiracy charge that carries a maximum punishment of 20 years behind bars. He was portrayed during a five-month trial as an unscrupulous politician who took bribes, rigged contracts and lived far beyond his means while in office until fall 2008.

Kilpatrick wore a surprised, puzzled look at times as U. S. District Judge Nancy Edmunds read the jury’s verdict: guilty of 24 charges, not guilty on three and no consensus on three more. Kilpatrick declined to speak to reporters as he left the courthouse.

Prosecutors said Kilpatrick ran a “private profit machine” out of Detroit’s City Hall. The government presented evidence to show he got a share of the spoils after ensuring that Bobby Ferguson’s excavating company was awarded millions in work from the water department.

Business owners said they were forced to hire Ferguson as a subcontractor or risk losing city contracts. Separately, fundraiser Emma Bell said she gave Kilpatrick more than $200,000 as his personal cut of political donations, pulling cash from her bra during private meetings. A high-ranking aide, Derrick Miller, told jurors that he often was the middle man, passing bribes from others.