“Crowning Glory: Art of the Americas,” a small show of terra cotta, wooden and ceramic artifacts from Mexico and Central America spanning more than 2,000 years is currently at the Walters through Oct. 7. The exhibit includes several pieces donated by the late John Bourne. All told, Bourne, who died in 2016, bequeathed 300 pre-Columbian artworks from a vast territory ranging from Mexico to Peru, and $4 million to the Walters. Marciari-Alexander acknowledged that for many of these pieces, the record of archaeological excavation is unknown, raising the possibility that they may originally have been stolen from the sites of ancient ruins. According to published news reports, looting in Latin and South America has been widespread since the mid-1980s.