Las Vegas police presented a third version on Friday of the timeline of events for the Las Vegas gunman who killed 58 people and himself, saying they responded immediately to the deadliest mass shooting in modern U.S. history.

Clark County Sheriff Joseph Lombardo, who oversees the Las Vegas police department, told reporters that gunman Stephen Paddock shot at Mandalay Bay hotel security guard Jesus Campos outside his room on Oct. 1 at about the same time he opened fire on the more than 20,000 concertgoers at an outdoor venue.

Previously, police said that Paddock shot Campos six minutes before he started firing on the crowd, raising questions as to whether police and hotel security could have acted faster to prevent casualties in the attack.