Authorities say that DNA on a cigarette butt found after the killings of a federal judge's mother and husband matches the Chicago electrician who killed himself during a traffic stop in Wisconsin this week and claimed responsibility for the slayings in a suicide note.

Chicago Police spokesman Matthew Jackson says the state police
crime lab confirms the link.

Police Superintendent Phil Cline said earlier today that in addition to the suicide note, the electrician, 57-year-old Bart Ross, also fit a witness description of a man seen leaving U.S. District Judge Joan Lefkow's home the day of the killings.

Police spokesman David Bayless stopped short of saying the case
is closed. But he says all the evidence points to Ross being the
lone killer and the investigation is "nearing a conclusion."

Bayless says investigators are going to continue analyzing evidence found in both the Lefkow home and Ross' minivan to "tie up loose ends."

(Copyright 2005 by The Associated Press. All Rights Reserved.)