Observation of a Narrow Charged State at 1876 MeV/<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mrow><mml:mi mathvariant="italic">c</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msup></mml:mrow></mml:math>Decaying to an Exotic Combination of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>K</mml:mi><mml:mi>π</mml:mi><mml:mi>π</mml:mi></mml:math>

We report evidence for the production of a new narrow charged state in ${e}^{+}{e}^{\ensuremath{-}}$ annihilation at a center-of-mass energy of 4.03 GeV. This state, which has a mass of 1876\ifmmode\pm\else\textpm\fi{} 15 MeV/${\mathit{c}}^{2}$, is observed in the exotic channel ${K}^{\ensuremath{\mp}}{\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}{\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}$, but not in the nonexotic channel ${K}^{\ensuremath{\mp}}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$. It is produced primarily in association with a system of mass 2.01\ifmmode\pm\else\textpm\fi{}0.02 GeV/${\mathit{c}}^{2}$. These characteristics are just those expected of a charged charmed meson.