From CBS News:
Sniper took picture of Trump rally shooter, saw him use rangefinder before assassination attempt, source says
"A sniper from a local tactical team deployed to assist the U.S. Secret Service at former President Donald Trump's
rally on Saturday took a picture of the
gunman and saw him looking through a rangefinder minutes before he
tried to assassinate the former president, a local law enforcement officer with direct knowledge of the events told CBS News.
The sniper was one of three snipers, members of local tactical teams, who were stationed inside the building that the shooter used in the attack, the officer said. The operations plan had them stationed inside, looking out windows toward the rally, scanning the crowd. The details about the three snipers were first reported by the local news outlet BeaverCountian.com.
One sniper inside spotted the gunman, Thomas Matthew Crooks, outside and looking up at the roof, observing the building and disappearing, according to the officer who spoke to CBS News. The sniper observed Crooks as he returned to the building, sat down and looked at his phone. At that point, one of the local snipers took a picture of Crooks.
Next, the local sniper observed Crooks looking through a rangefinder, an instrument routinely used by marksmen to determine the distance of a target, and he immediately radioed to the command post, according to the local law enforcement officer. The local sniper also attempted to send the photo of the gunman up the chain of command."