Sniper accused 'wanted to kill wife'

US investigators believe the man accused of being the Washington sniper went on a shooting spree because he planned to murder his ex-wife in what would appear to be a random killing.

John Allen Muhammad’s second ex-wife, Mildred Green, lives in Clinton, Maryland, 15 miles south-east of Washington DC, which police think is why he chose the capital and its suburbs as his killing ground.

Officers believe he planned to terrorise the area with random sniper attacks and then shoot Ms Green.

The news came as it was revealed Muhammad and his accomplice John Lee Malvo - already linked to ten fatal shootings in the Washington DC area - have been charged with a murder in Louisiana. Police are also looking into numerous unsolved killings in Arizona, California, Connecticut, Michigan, Oregon, Tennessee and Washington State.

Investigators reportedly said they had all but eliminated terrorist ties or political ideologies as a motive.

Instead detectives are working on the theory that the rampage was sparked by Muhammad’s increasing anger at Ms Green after their marriage failed and she won custody of their three children.

Muhammad and Malvo have so far been charged with six sniper shootings in Maryland, where they remain in federal custody, and one in Virginia. They have now also been charged with the killing of 45-year-old Hong Im Ballenger in Baton Rouge on September 23, police chief Pat Englade said .

The victim was shot to death as she was about to get into her car after work.

Chief Englade said till receipts found in a Chevrolet Caprice in which the pair were arrested on October 24 and which was allegedly rigged for shooting from inside, placed them in Baton Rouge on the date of the killing.

Federal, Maryland and Virginia state law enforcement officials are still arguing over where to try the pair first, and which jurisdiction has the best chance of imposing the death penalty if convicted.