The police were notified by the theater's cashier and responded by surrounding the theater. Oswald was arrested after a brief struggle. Twelve people who witnessed the shooting or its aftermath were mentioned in The Warren Report. Domingo Benavides saw Tippit standing by the left door of his parked police car, and a man standing on the right side of the car. He then heard shots and saw Tippit fall to the ground. Benavides stopped his pickup truck on the opposite side of the street from Tippit's car. He observed the shooter fleeing the scene and removing spent cartridge cases from his gun as he left. Benavides waited in his truck until the gunman disappeared before assisting Tippit. He then reported the shooting to police headquarters, using the radio in Tippit's car. Helen Markham witnessed the shooting and then saw a man with a gun in his hand leave the scene. Markham identified Oswald as Tippit's killer in a police lineup she viewed that evening. Barbara Davis and her sister-in-law Virginia Davis heard the shots and saw a man crossing their lawn, shaking his revolver, as if he were emptying it of cartridge cases. Later, the women found two cartridge cases near the crime scene and handed the cases over to police. That evening, Barbara Davis and Virginia Davis were taken to a lineup and both Davises picked out Oswald as the man whom they had seen. Taxicab driver William Scoggins testified that he was sitting nearby in his cab when he saw Tippit's police car pull up alongside a man on the sidewalk. Scoggins heard three or four shots and then saw Tippit fall to the ground. As Scoggins crouched behind his cab, the man passed within 12 feet of him, pistol in hand, muttering what sounded to him like, "poor dumb cop" or "poor damn cop." The next day, Scoggins viewed a police lineup and identified Oswald as the man whom he had seen with the pistol. The Commission also named several other witnesses who were not at the scene of the murder, but who identified Oswald running between the murder scene and the Texas Theatre, where Oswald was subsequently arrested. Four cartridge cases were found at the scene by eyewitnesses. It was the unanimous testimony of expert witnesses before the Warren Commission that these spent cartridge cases were fired from the revolver in Oswald's possession to the exclusion of all other weapons. Upon his arrest and during subsequent questionings by police, Lee Harvey Oswald denied any involvement in Tippit's murder.