Google is conducting a broad internal investigation to determine whether Russian-linked entities used its ads or services to try to manipulate voters ahead of the U.S. election, according to a person familiar with the matter, a move that comes after Facebook and Twitter said Russian actors used their sites. Google, part of Alphabet, is also talking with congressional officials who are investigating Russian efforts to influence the election, and plans to share its findings with them once completed, this person said. Congressional leaders have scrutinized Facebook and Twitter this month for Russian activity on their sites—and criticized the tech companies...