Police in Iowa, Illinois and Wisconsin are still looking for a man who authorities say killed his adopted son. Several sightings were reported in the Davenport area on Thursday. Thirty-year-old Douglas Maring led police on a chase early Wednesday.

Eight-year-old Anthony Maring was in the truck with his step-father and authorities say Maring stabbed the boy in the chest. The child died a short while later in a Dubuque hospital. Maring ran from his crashed pick-up in Galena and stole a car to escape.

Relatives are pleading with Maring to stop running. “I hope and pray that he turns himself in,” one relative told reporters. Maring’s wife, Heidi, says her husband became suicidal after she told him she planned to file for divorce. Maring, who worked in Dubuque, sent her a suicide note in the form of a cell phone text message.

Heidi Maring spoke at a news conference on Thursday. “Doug, please turn yourself in — for Anthony. I know you loved him. Please stop what you’re doing and think of Anthony and let’s help be put to rest,” she said.

Brian Melton, the sheriff in Jo Daviess County, Illinois, told reporters the search area has expanded beyond Dubuque and Galena. “We’ve had law enforcement calling us from all over offering us their assistance,” he says. “It’s an active search beyond the tri-state area.”

Maring faces a first-degree murder charge if he surrenders. Authorities consider Maring armed and dangerous and they are asking for the public’s help in finding him. Investigators believe he’s driving a stolen 2005 Chevy Malibu with the Illinois license plate number 825 4607.