I would never leave anything in a parked car anywhere, ESPECIALLY IN D.C. John Solomon obviously has not spent too much time in the ‘hood.
Although I have tinted windows, I even stow my colorful plastic shopping bags under the seats, to avoid a break-in. I also learned to leave any little dings in the fenders or bumpers to discourage outright car theft, having once lived in car-theft capital, Philly/New Jersey. It helps.