A vote to not convict is an acquittal.
acquittal noun
ac·quit·tal | \ ə-ˈkwit-ᵊl \
Legal Definition of acquittal
1: release or discharge from debt or other liability
2: a setting free or deliverance from the charge of an offense by verdict of a jury, judgment of a court, or other legal process
Synonyms & Antonyms for acquittal
clearing, exculpation, exoneration, vindication
https://www.merriam-webster.com/dictionary/acquittal