Retailers are on high alert in Sherbrooke, Que., after more than a dozen dirty needles were found in clothing in stores.

The police chief in Sherbrooke, Que. is urging people not to panic as more dirty needles turn up tucked into pockets of clothes on display in the city's shopping areas.

A forensic scientist testified Friday that two cotton balls and a syringe needle allegedly saved after a steroids injection tested positive for Roger Clemens's DNA, a key moment as the government tries to prove the former pitcher used performance-enhancing drugs.

Exhibit 52C was the semi-crushed Miller Lite beer can. Exhibit 52D was the FedEx box that once contained the beer can. Then came exhibits of gauze, tissues, syringes, cotton balls and needles, some of which were once inside the beer can, using up letters of the alphabet all the way to X.