Authorities arrested a suspect and charged him with murder Monday in the brazen Manhattan killing of UnitedHealthcare’s CEO after a quick-thinking McDonald’s customer in Pennsylvania spotted a man who officers found with a gun, mask and writings linking him to the ambush. The chance sighting at the restaurant in Altoona led to a dramatic break in a challenging but fast-moving investigation that captivated the public in the five days since the shooting that shook the business world. Luigi Nicholas Mangione, a 26-year-old Ivy League graduate from a prominent Maryland real estate family, had a gun believed to be the one used in last Wednesday’s shooting of Brian Thompson, as well as writings suggesting anger with corporate America, police said. Late Monday, Manhattan prosecutors filed murder and other charges against Mangione, according to an online court docket. He remained jailed in Pennsylvania, where he was charged with possession of an unlicensed firearm, forgery and providing false identification to police. MORE: https://www.wthr.com/article/news/nation-world/hunt-for-unitedhealthcare-ceo-killer-continues/507-97759326-3bb4-48e3-8c73-3759dfdc9930