Maybe the rest of you can make sense of it.
It says local police were in an "adjacent building."
It also says:
The gunman used the roof of the one-story building closest to the stage from which to fire his AR-15-type weapon. But agencies are offering different accounts about which building local law enforcement used as a staging area and a perch for the three local officers called counter snipers. These officers were watching over the crowd as it gathered in the secure zone, a local law enforcement official, who was not authorized to give public statements, said in an interview with the Times. It was the two-floor building, the one behind the warehouse used by the gunman, where those snipers were stationed by the windows, the official said.
The photo in your link, along with the details, explains a lot. The local counter-sniper teams were inside the building behind the sniper, inside the 2nd story windows to the far left of the building. They would need to stick their heads out the window and look to their left (viewer’s right) to see the would-be assassin. The assassin was at least partially obscured from the view of the SS counter-sniper team by the large tree between them. The SS protection team would have certainly identified this area and implemented measures to secure it. Placing the police counter-sniper team on the roof of the 2 story building would have given them visual coverage of the assassin’s location.
Several sources have reported that the local team was supposed to be on the roof, but changed their location to inside on the 2nd floor. When they informed the SS of the change, that should have been reversed/denied. Someone obviously didn’t do their job.