A male victim suffered life-threatening injuries after being shot in the Grove Hall section of Dorchester on Saturday night, Boston police said. The shooting took place near 504 Blue Hill Ave. just before 9:45 p.m., said Officer Nicole Grant, a police spokeswoman. Grant said the victim was transported to Boston Medical Center with life-threatening injuries. At the scene, a witness who asked not to be named because he feared for his safety said he was speaking with the victim when shots rang out. “We were talking, and I heard shots, and I ran for my life,” the man said. “He looked to see where the shots were coming from, and they hit him.” The man said the victim was shot in the head.