I think the risk of a 94 year old bolting would be pretty low, so there’s not much downside, and the publicity might turn up some fresh leads.
Suppose you had a guy you thought was him (same age, general description, similar facial bone structure, German accent, etc.)
Leak the information that you've got a solid lead on the war criminal, and if he twitches, he's worth a closer look.
This guy:
CA: Body found in Oakland Hills is Nina Reiser
Tipped his hand when a fellow inmate noticed that he rushed to the TV when a report of a body being discovered in the Oakland Hills came on. The inmate thought it was distinctly odd that he was so visibly relieved when they identified the body as that of a black male...