"There was DNA on the knife and ... on a pair of trousers," chief prosecutor Agneta Blidberg told a Swedish radio station Thursday, the BBC said.
Lindh, a popular politician seen as a potential prime minister, was stabbed on Sept. 10 and died the next day. A suspect, Mijailo Mijailovic, was arrested soon after but denies any involvement and has not been charged.
But his lawyer, Peter Althin, is expected to receive roughly 1,000 pages of notes from the investigation. Althin will have three weeks to read the material before charges can be filed.
Sweden was shocked by the killing of Lindh, 46, as she shopped by herself in a downtown Stockholm department store. It came in the final days of a campaign in which she had been trying to persuade Swedes to vote in favor of adopting the euro as its currency.