The Brief Prince George's County police warned of an increase in online marketplace robberies. Prince George’s County police issued a warning about a dangerous nationwide trend hitting the community: online marketplace meetups devolving into violent robberies and, in some cases, death. What we know:Department officials reported nearly 50 related incidents have occurred across Prince George’s County so far this year. "Sometimes we can tell you’re getting set up, or things escalate once you are engaged in the transaction," said Prince George’s County Police Chief George Nader. "I think it’s more about the parenting," said Prince George’s County resident Mina Akar.