American investment giant BlackRock pulled an advertisement featuring the gun-nut wannabe assassin who came within inches of blowing off Donald Trump’s head over the weekend. Thomas Matthew Crooks – the 20-year-old Bethel Park native who fired eight shots at ex-President Trump in Butler, Pennsylvania on Saturday evening – once appeared in a BlackRock ad filmed at Bethel Park High School. A rep for the investment monolith confirmed: “In 2022, we ran an ad featuring a teacher from Bethel Park High School, in which several unpaid students briefly appeared in the background, including Thomas Matth…