BALLISTIC evidence conclusively links the death of a woman shot in the head in a suburban parking lot with eight other killings by the Washington-area sniper, authorities said yesterday.

Police investigations into the identity of the mystery sniper were stepped up today after a woman was shot and killed outside a shopping centre near Washington DC.

Their unsigned Visa debit card was rejected by the travel agency computer, and the clerk would not let them write a cheque for the two first-class airline tickets to Los Angeles they wanted to buy.