Think, McFly.
"Wrongful convictions" don't occur because the cops don't understand the law. As a matter of fact, convictions occur in a court, in front of a judge and are subject to being argued by opposing legal counsel. Cops don't convict anyone.
We couldn't even book a suspect into the County Jail without our booking report being reviewed by the Jail staff. Those reports include a summary (written by the booking officer) of the investigation citing the alleged facts which meet each element of the offense for which that individual was being booked. If a cop's report summary didn't meet all of those elements for that offense the jail wouldn't accept the booking because they didn't want the liability.
I'll bet you didn't know that, did you?
After booking, each arrest report is reviewed by the DA before they decide which cases to to prosecute and which to drop. So simply being arrested never automaticall leads to a prosecution, let alone a conviction.
Now the cops can and do make mistakes with the facts of the event or tell untruths about those facts, which when being relied upon in court can lead to wrongful convictions, but that has nothing to do with what the cops do or don't understand about the law. Those factual errors and omissions have other, more serious causes.