Make sure the scenarios aren't too easy. Most officers would step in if they saw a fellow officer about to pocket cash confiscated from a drug dealer. But suppose instead, your partner was trying to intimidate a subject into permitting a "consent" search of the trunk of his car by threatening to arrest him for obstruction--when the subject had legitimately exercised his Constitutional right to refuse consent, and there were neither real grounds for an obstruction charge nor probable cause for a search. Or what if your sergeant ordered you to empty and tag as evidence the beer cans seized in an underage drinking bust, but started to walk away with a bottle of Jack Daniel's, saying, "No reason to waste good whiskey." What would you do then?
Implementing Shared Responsibility may not prevent every incidence of misconduct, just as establishing a policy requiring mandatory reporting hasn't always worked to breach the blue wall of silence. But the more we work proactively to protect our brothers and sisters of the badge from all the hazards of the job, the less need we'll have for that wall. It may just crumble from disuse.