Death Records Now

This is a Question about Korean War service records, If everyone that is closely related to my great uncle Albert W. smith has passed away will I run into problems getting the Service records,or can I have my mother who is his niece sign for them, We know that Albert was married but don’t his wife name and had a son named Rick smith.
Albert Smith was killed in the Korean War when he was captured by the North Koreans and killed in a firing squad.
I have had no luck tracing Albert Smith past a certian date of course because census records stop or should I try and get a death certificate and will that state his wife name and how do I get a death certificate for someone killed in War? Here is all I know about
Albert Woodrow Smith
Born: 30 Oct 1918
Atlanta,Georgia
30 Jun 1951
North Korea
Korean War Honor Roll
Service Number O-2262340
Died while Prisoner of War
Died June 30, 1951 in KoreaFirst Lieutenant
Also know his is Buried in the National Cemetery,Hawaii
Albert is on the 1930 census with his mother Minnie P Smith in Dyersburg,Tennessee

*Name: Albert W Smith
Birth Date: 30 Oct 1918
Rank: Second Lieutenant
Service Number: 0002262340
Dossier Number: C8055800
Source: Repatriated Korean Conflict POWs
* First Lieutenant Smith was a member of the 23rd Infantry Regiment, 2nd Infantry Division. He was taken Prisoner of War while fighting the enemy in North Korea on November 30, 1950 and died while a prisoner on June 30, 1951.

* World War Two service
Name: Albert Woodrow Smith
Ship Name: Bunker Hill
Ship number: CV-17
Enlistment Date: 30 Sep 1944
Roll: MIUSA2006_082834
Yeah I have actually found the record listed in the National archives I’m wondering If I’m going to have trouble obtaining the records since I’m a great Nephew.

You may be able to get his complete service record through the National Archives and Records Administration (NARA). I think the form you want in the DD-214.

Their website is not responding at this moment, but it should be: