The Catholic Diocese of Brownsville is working to gather information on Sunday’s arrest of a nun as she was walking to church in McAllen, calling circumstances behind the actions by federal immigration agents “wildly disturbing.” U.S. Immigration and Customs Enforcement officials detained Sister Leticia “Letty” Ugboaja, a 56-year-old nun from Nigeria, and released her later Sunday after South Texas members of Congress intervened. “There are many questions remaining about the circumstances surrounding Sister Letty’s arrest and detention,” Bishop Daniel E. Flores said in a statement. “For now, it is clear that Homeland Security enforcement protocols that make it possible for...