In the United States, prosecutors are under a lot of pressure to get convictions under their belt or risk being seen as "soft on crime" and lose their position. Due to this, there could be a lot of corruption and fabrication/hiding exculpatory evidence that could be used to prove someone did not commit the crime.
It's really comes down to corruption if they are aware of what they're doing and ignorance if they believe they're right.
In the United States, prosecutors are under a lot of pressure to get convictions under their belt or risk being seen as "soft on crime" and lose their position. Due to this, there could be a lot of corruption and fabrication/hiding exculpatory evidence that could be used to prove someone did not commit the crime.
It's really comes down to corruption if they are aware of what they're doing and ignorance if they believe they're right.