MADISON, Wis. — The Wisconsin Supreme Court has upheld the conviction of a man who shot and injured two Milwaukee police officers in 2009.

Julius Burton was sentenced to 80 years in prison after pleading guilty to charges related to the shooting of the officers. Burton wanted to withdraw his pleas, arguing that his former attorney and the lower court didn't properly advise him, but a state appeals court denied his request.

The state Supreme Court on Wednesday unanimously upheld the lower court's ruling, rejecting Burton's attempt to withdraw his guilty plea.

The officers were monitoring students leaving a high school when they saw Burton violating a city ordinance. Burton shot both officers at close range in their faces.

The officers returned to duty about a year later.