PC 851.6 says that if you're detained, but not arrested, your criminal history will reflect the incident as a "detention only". If your arrested but later released under PC 849, you'll be given a certificate saying you were only detained and your criminal history is supposed to reflect that. In other words, PC 851.6 does not delete anything from your criminal history but ensures that it will show up as a "detention only".
PC 851.8, on the other hand, allows a person who is arrested to petition to have that arrest record sealed and destroyed (meaning it is truly erased from your criminal history). The procedures vary depending on whether charges were filed.
If you go to trial and are acquitted, the arrest and the subsequent charges will appear on your California criminal history along with an entry saying you were acquitted. You could always try to get it erased under PC 851.8, but I don't see that modifying it to a "detention only" would apply.
Hope that helps.
PC 851.6 only applies to a person who has been arrested and released without an accusatory pleading being filed. If you had a trial there was an accusatory pleading. Your only shot would be 851.8 which under the facts you recite you wouldn't get. There is also a downside of an 851.8 petition if you lose because then you will have created a public record that while you were dismissed you were NOT innocent. Absent the petition the whole procedure from arrest to acquittal is published only in your rap sheet which is not available to the public.
The standard for sealing the arrest records is that it is established that the defendant is factually innocent of the charges. It is the defendant's burden to establish innocence either from the record or additional evidence presented. The reason for the dismissal at trial is highly significant as to eligibility for the finding of factual innocence. If the jury is hung, it would be virtually impossible to establish factual innocence. It is most likely where the trial establishes that the defendant did not in fact commit the crime. Outside of old Perry Mason episodes where the witnesses break down and admit lying, this doesn’t happen very often in real life. cent of the charges. It is the defendant's burden to establish innocense either from the record or additional evidence presented. The reason for the dismissal at trial is highly significant as to eligibility for the finding of factual innocense. If the jury is hung, it would be virtually impossible to establish factual innocense. It is most likely where the trial establishes that the defendant did not in fact comitt the crime. If this is the case, it is unlikely that the case would have gone to trial.
You would need to petition under PC 851.8, but those are hard to get even with a jury acquittal. The trial judge would have to have concluded that defendant was factually innocent. Check out the case People v. Adair (2003 Cal.) for the legal standard.
I once had a jury trial with an acquittal on battery and assault charges on self-defense/defense of another. The petition for factual innocence was denied because there was evidence upon which a reasonable jury could have convicted.