A police dog searching for a handgun in a snowbank in downtown Lawrence accidentally fired the weapon with his paw, according to the Essex County sheriff’s office. No one was harmed, officials said. The sheriff’s office was called to help Lawrence Police after gunshots were heard in the downtown area, which has a busy nightlife scene on Friday and Saturday nights. According to a spokesman for the sheriff’s office, police pulled over a car with five people thought to be involved in a reported shooting. A man got out and allegedly “hid something in a snowbank,” the spokesman said. A police dog and his handler were searching the snowbank when the dog began digging furiously. “When he was digging, his paw hit the trigger mechanism, which discharged the weapon,” the spokesman said.