The crossed keys symbolize the keys to Heaven as promised to Saint Peter.  The crozier, or pastoral staff, symbolizes episcopal authority as Saint Peter was first Bishop of Rome.  The crozier and keys together form Chi Rho, which are the first two letters in the Greek alphabet spelling of Christ.  The upside down cross is a reminder that St. Peter was crucified head down on a cross.  The red background of the shield symbolizes the Blood of Christ.  The shield was designed by Patrick Edmiston in 2008.