Controversy over Trump's Arlington Cemetery visit

Donald Trump's campaign was involved in an altercation at Arlington National Cemetery over filming after a wreath-laying ceremony. The cemetery cited federal law prohibiting political activity, including photography. A Trump spokesperson claimed the cemetery official was having a mental health episode. Trump visited on the anniversary of a bombing that killed 13 service members during the US withdrawal from Afghanistan.

What event was taking place at Arlington National Cemetery when the altercation occurred?

What was the reason for the altercation between Trump's campaign members and the cemetery official?

What did the cemetery state about political activity at Army cemeteries?

How did the Trump spokesperson describe the cemetery official involved in the altercation?

What significant event was being commemorated during Trump's visit to the cemetery?