An elderly American has been arrested after a gunman was caught on camera walking up to environmental protesters blocking a Panamanian highway Tuesday and blasting two of them to death. Disturbing footage showed a man with gray hair and glasses casually approaching the blockade on the Pan-American Highway and waving his finger while arguing with the demonstrators — before pulling out a gun and opening fire. Other footage showed people standing around bodies in the road in the Chame sector west of Panama City as well as the gunman being cuffed and led to a squad car. Police later shared...