The conviction of a former police officer for the murder of George Floyd has opened up a space where a culture of defensiveness inside law enforcement in the US may begin to shift

As a former law enforcement ­officer and police ethics instructor, it was the testimonies given during the trial of Derek Chauvin for the murder of George Floyd by several Minneapolis police officers that particularly struck me. All were testifying for the prosecution; not a single officer from Chauvin’s former department testified for the defence. In Catholic Social Teaching, the civil authorities, including police officers, have the right and duty to use armed force in “legitimate defence” of themselves and fellow citizens – but that does not mean being defensive about their job and their actions is always legitimate.

The “blue wall of silence” – buttressed by powerful police unions – almost always stands as an impenetrable fortification protecting police from convictions for corruption, brutality, racism and excessive force. When Chief Medaria Arradondo testified that Chauvin’s conduct had violated his department’s policy and was “certainly not part of our ethics or values”, and Lieutenant Richard Zimmerman, head of the department’s homicide unit, testified that Chauvin’s kneeling on Floyd’s neck was “totally unnecessary”, we saw the beginnings of a fissure in the repulsive rampart.