I checked with a friend of mine at Army Casualty about requesting IDPF's.
The correct address is
The Total Army Personnel Command ATTN: TAPC-PER 2461 Eisenhower Ave Alexandria, VA 22331-0482
They state the post card is not correct. It should be in a letter and requested under the provisions of the Freedom of Information Act or as next of kin. Include your name, address, city, state & zip. Print your name followed by your signature.
They will acknowledge receipt of your letter and will let you know approximatley how long the wait will be.