You might start by seeing if his name is in THIS LIST.
Stolen Valor Act of 2005 - Amends the federal criminal code to expand the prohibition against wearing, manufacturing, or selling military decorations or medals without legal authorization to prohibit purchasing, soliciting, mailing, shipping, importing, exporting, producing blank certificates of receipt for, advertising, trading, bartering, or exchanging such decorations or medals without authorization.
Prohibits falsely representing oneself as having been awarded any decoration or medal authorized by Congress for the Armed Forces or any of the service medals or badges.
Increases penalties for violations if the offense involves a distinguished service cross, an Air Force Cross, a Navy Cross, a silver star, or a Purple Heart.
Under the Stolen Valor Act, falsely claiming to have received the Navy Cross, Air Force Cross, Distinguished Service Medal, Silver Star or Purple Heart would double the maximum penalty to up to a year in prison, bringing those medals in line with the Medal of Honor.