It seems that anyone can enter information, but is likely that his wife or the Tyler police department would be the best candidates to do so. It asks for a lot of information that those two are most likely to know. (Some are required entries) The user guide is here: https://www.findthemissing.org/documents/NamUsUserGuide.pdfWho would normally make sure he'd be listed?
The instructions for entering a person begin on page 9 of the document.