Authorities knocked on doors and scoured yards Monday in search of any video or other evidence that might lead them to the Brown University gunman, whose face was covered or not visible in footage captured before and after the weekend attack that killed two students and wounded nine others. Officials released three new videos of the man they believe carried out Saturday's attack that show him wearing a mask and a dark two-tone jacket. Although his face wasn't visible, the footage from about two hours before the shooting provided the clearest images yet of the suspect. The FBI said the man is about 5 feet, 8 inches (173 centimetres) tall, with a stocky build. The agency offered a USD 50,000 reward for information leading to the identification, arrest and conviction of the person responsible. "We're asking for the public's assistance, Providence's police chief, Col Oscar Perez, said at a news conference, urging people who might recognise the suspect to call a tip line. Police renewed