Rep. Eli Crane Climbs Roof Where Trump Shooter Died, Questions Secret Service

Rep. Eli Crane is checking out the perch where Thomas Matthew Crooks fired at Donald Trump ... and he's questioning how the shooter slipped past the Secret Service.

The Republican Congressman from Arizona is in Butler, PA investigating the scene of the Trump rally shooting ... and he's sharing video from the infamous sloped roof where Crooks opened fire on Trump before Secret Service countersnipers killed him.

A former Navy SEAL sniper himself, Rep. Crane disputes the Secret Service claim it didn't have personnel on the roof because of its slope ... and he's wondering why there wasn't a sniper posted on a nearby water tower, which offers a clear view of the roof where Crooks took up position.

Rep. Crane also shows the second-floor window where Secret Service agents were allegedly keeping watch.

Crane even went into the room with the second-story window ... showing the view from inside and wondering how Crooks got up on the roof undetected.

Of course, folks at the rally saw Crooks on the roof and tried to alert law enforcement . Still, immediately after a sheriff's deputy tried to engage him, Crooks was able to get off several shots at Trump.

The head of the Secret Service, Kimberly Cheatle , was grilled Monday on Capitol Hill ... and, clearly, Crane will have more questions for her when he gets done in Butler.