How exactly do you propose to prove something (planting evidence) didn't happen?
Maybe I have too low expectation about USA interface between law enforcement and judiciary, but here in Poland there were many high-profile cases of misconduct of public prosecutors that colluded with the police. The only "proven" cases were about purposefuly destroying evidence: breaking CDs that held incriminating recordings, wiping weapons to remove fingerprints, agreeing to single version of testimony etc. They used procedural quirks to prevent defence from challenging those "mishaps" (like in one high-profile case with broken CD, they argued defence-held copy cannot be submitted, because of continuous custody requirements). Cases with planted evidence were always he-said-she-said, because when police writes a search report where they said you had something, then you have no way to challenge that.
May I add, fraud around those arrest/search reports (however they're called it English) is rampant. It starts with simple things, like notifying the subject about right to attorney. They just tick a box that you declined to summon attorney, and you have no way to challenge that, other than refusing to sign the paper, act of which carries no value.
We're deep, deep into speculation here. I'd wager that as the profile of the case goes up, so too does the dilligence and carefulness of the evidence chain of custody.
Maybe I have too low expectation about USA interface between law enforcement and judiciary, but here in Poland there were many high-profile cases of misconduct of public prosecutors that colluded with the police. The only "proven" cases were about purposefuly destroying evidence: breaking CDs that held incriminating recordings, wiping weapons to remove fingerprints, agreeing to single version of testimony etc. They used procedural quirks to prevent defence from challenging those "mishaps" (like in one high-profile case with broken CD, they argued defence-held copy cannot be submitted, because of continuous custody requirements). Cases with planted evidence were always he-said-she-said, because when police writes a search report where they said you had something, then you have no way to challenge that.
May I add, fraud around those arrest/search reports (however they're called it English) is rampant. It starts with simple things, like notifying the subject about right to attorney. They just tick a box that you declined to summon attorney, and you have no way to challenge that, other than refusing to sign the paper, act of which carries no value.