CHICAGO, Illinois (CNN) -- A man who committed suicide during a routine traffic stop near Milwaukee, Wisconsin, left a note claiming responsibility for killing the husband and mother of a federal judge in Chicago, police sources said Thursday.
The man, Bart Ross, had appeared before U.S. District Judge Joan Lefkow in the past, the Chicago Tribune reported Thursday. The paper said Lefkow had heard a medical malpractice lawsuit Ross had filed against the University of Illinois over cancer treatment. Ross had represented himself, and Lefkow dismissed the case, according to the Tribune.
Investigators were looking at Ross -- but not intensely -- in the deaths of Michael Lefkow, 64, and Donna Grace Humphrey, 89, police told CNN. The judge found their bodies in her home February 28; both had been shot to death.
On Wednesday night, police in West Allis, Wisconsin, pulled Ross over for a faulty taillight, Jim Warren, deputy managing editor of the Tribune, told CNN. The man then shot himself.
A note left in the minivan said he had killed Lefkow and Humphrey, the Tribune reported. One of the details in the note was where Lefkow's body had been found, something police had not released, Warren said.
Ross' note blamed the judge for the loss of his home, family and life, Warren said. He previously lived on the North Side of Chicago, but neighbors told the Tribune they had not seen him in several months, and there were indications he may have been living in his van, Warren said.
The Tribune also reported that police found 300 .22-caliber bullets in Ross' van -- the same caliber as casings found in the Lefkow home, Warren said.
A Chicago police spokesman told CNN that detectives were dispatched overnight to Wisconsin to investigate. West Allis police were holding a news conference Thursday morning.
Police initially said that white supremacist leader Matt Hale, 33, may have been involved in the deaths, but Hale denied any role.
Hale, who is awaiting sentencing, was convicted in 2004 of trying to have the judge killed over a ruling in a trademark dispute
