How many more times?
Insufficient evidence is exactly the same as not guilty is exactly the same as innocent.
If you are charged with an offence, the case goes to court, you are presumed innocent unless proven guilty, you are found not guilty, then obviously the evidence was not sufficient to convict, i.e. the evidence was insufficient, you are innocent.
exonerateverb
past tense: exonerated; past participle: exonerated
1.
(of an official body) absolve (someone) from blame for a fault or wrongdoing.
"an inquiry exonerated those involved"
synonyms: absolve, clear, acquit, declare innocent, find innocent, pronounce not guilty, discharge
p.s. Amanda did not wash Meredith's blood from her. Even if guilty this could never be proven, so it just goes to show what an embarrassment these judicial facts are.