What evidence does an officer need to write me a ticket for an Open Container violation?
Well, whatever the officer thinks is justification for the ticket. The legal term here is “reasonable suspicion”, which is an awfully low standard. Not to be silly, but for example here in Austin, they don’t have to convene a jury, or summon a judge out on Sixth Street to merely issue you a ticket. Most folks who have gotten traffic tickets have heard the officer say that their signature on the copy of the ticket is not an admission of guilt, just a promise to show up in court and take care of it. Basically, a ticket is just a piece of paper, stating the officer’s belief that a crime has been committed.