DNA from Anwar

Why the Police desperately need Anwar's DNA again? Don't they have it once? How many times do they want to repeat the same thing. Is this professional as they are saying? What is the motive for this? Remember, in 1998, Musa Hassan is only Superintendant Assistant Commissioner while Gani Patail is only ordinary lawyer... but now, they're Inspector General Police and Attorney General respectively. Is there any connection or correlation if you can find it?