Complex sentence: Owens was never apprehended, probably because the Virginia authorities saw no need to chase a pirate robbing Marylanders, and because once the Virginia economy improved in the late 1880s, Owens and his crew went back to oyster fishing and ceased their criminal activities.
Split into simpler sentences: Owens was never apprehended, probably because the Virginia authorities saw no need to chase a pirate robbing Marylanders. Once the Virginia economy improved in the late 1880's, it is suspected that Owens and his crew went back to oyster fishing and ceased their criminal activities.