MADISON, Wis. -

A criminologist said Republican Gov. Scott Walker's campaign misrepresented his comments about Milwaukee Police Department crime statistics in a campaign ad.

The Milwaukee Journal Sentinel newspaper reported last month that Milwaukee police misclassified hundreds of violent crimes as minor assaults. Walker's campaign launched an ad accusing his Democratic challenger, Milwaukee Mayor Tom Barrett, of lying about the statistics to make the city's crime rate look better.

The ad flashes a partial quote criminologist Sam Walker gave the newspaper saying the misclassifications are suspicious, improper, and represent a failure of leadership next to a shot of Barrett.

Walker said he was referring to police leadership, not the mayor. He said elected officials usually accept data police give them.

Walker campaign spokeswoman Ciara Matthews didn't immediately return a message.