Hegseth has tattoos and was termed an "Insider Threat."

 Two Internet source links, Strib carrying a lengthy AP item, and Daily Mail, with visuals of tattoos and text.

https://www.startribune.com/trump-defense-pick-had-been-flagged-by-fellow-service-member-as-possible-insider-threat/601181381

https://www.dailymail.co.uk/news/article-14085003/white-house-blame-game-blood-bath.html

They are worthwhile reading about Trump's initial DOD nominee.

There is also Strib carrying a WaPo item about a sexual assault allegation (no charges filed against Hegseth)

https://www.startribune.com/trump-team-weighs-pentagon-pick-after-sexual-assault-allegation/601181500

Presumably this will sift through a re-vetting, or be a Senate topic set at a confirmation hearing, if there is one.