Hypersonic bullets. Did not find anything specific about the US having or testing hypersonic bullets. But they exist. Secret service might want to take note. Not saying anything like this was used. Just going where the digging is taking me.
https://www.eurasiantimes.com/after-hypersonic-missiles-russia-is-now-ready-to-field-hypersonic/amp/.
https://asiatimes.com/2022/08/china-testing-hypersonic-bullets-on-live-targets/