"Mary Ellen Walker, an attorney in the U.S. Justice Department, states . . ." is a complete citation of a credible source.
a) "Mary Ellen Walker, an attorney in the U.S. Justice Department, states . . ."
b) "According to a lawyer, Mary Ellen Walker, in the U.S. Justice Department . . ."
c) "Mary Ellen Walker is an attorney who works at the U.S. Justice Department."
d) "From the U.S. Justice Department, an attorney named Mary Ellen Walker has stated . . ."
