Aurora police were called Saturday when the man walked into the McDonald's at 14251 East Colfax Avenue and did not know who he was.
Police reported Tuesday night he was identified as a 23-year-old missing from New Mexico since Thursday. It is not known how he got to Colorado.
Police say his fingerprints were run through a national database but there were no matches.
Police say a medical evaluation shows no sign of injury or trauma.
The man's family is coming to Colorado to bring him home.
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