HOUSTON—A 51-year-old man who had been on the run after being accused of fatally shooting a Houston-area deputy during a traffic stop this past weekend has been arrested in Mexico, authorities announced Wednesday. Oscar Rosales was taken into custody by Mexican law enforcement early Wednesday morning, Houston police said on Twitter. “We are working with our law enforcement partners to begin the process of returning Rosales to Harris County,” Houston police said. Rosales was found in Ciudad Acuña, Mexico, located across the U.S.-Mexico border from Del Rio, Texas, according to the U.S. Marshals Service. A reward of $60,000 had been offered for information leading to his arrest. Harris County Precinct 5 Cpl. Charles Galloway, 47, was shot and killed around 12:45 a.m. on Sunday after pulling over a Toyota Avalon. Authorities allege Rosales got out of his vehicle, fired multiple shots at Galloway with some type of assault rifle and …