CHICAGO — The 15-year-old grandson of Rep. Danny Davis, a longtime U.S. House member, was fatally shot Friday in a dispute that may have started over a pair of gym shoes, police said.

Police had not yet released the name of the victim, but confirmed he was the teenage grandson of Davis, who represents a district that includes part of Chicago and the city's western suburbs.

The boy was at his home in the city’s Englewood neighborhood on the city’s South Side around 6:45 p.m. CT Friday when two assailants broke in and began arguing with the boy, according to police.

“That dispute escalated and turned physical and one of the offenders pulled out a gun and shot the victim in the head,” said Chicago Police spokesman Anthony Guglielmi, adding that the dispute was possibly over gym shoes.

The shooting is the latest grim incident in what is shaping up to be the most violent year in Chicago since the late 1990s.

No one was in police custody late Friday, but Guglielmi said detectives have “very good leads” on the case.

The city has recorded 643 murders through Nov. 6 — a 55% increase compared to the same period last year, according to police department data.

Police and Mayor Rahm Emanuel have blamed the current spike in street violence on increased gang activity and gun laws that they say aren’t strong enough to deter convicted felons from carrying and using weapons. The vast majority of the murders have occurred in predominantly African-American neighborhoods on the city's South and West sides.

Davis, a Democrat, was first elected to the House in 1996.

He told the Chicago Tribune that his grandson was a high school sophomore.

“He was a typical 15-year-old,’’ Davis told the paper. “He liked basketball. If you listened to him he was a basketball star, but he liked basketball and music. All those kinds of things. He was an avid sports fan, he knew all about, you know, the stats of different players.”

Follow USA TODAY Chicago correspondent Aamer Madhani on Twitter: @AamerISmad