How do we stop BS-spewing "bite mark analysis" experts, and malicious FBI crime lab "results", and habitually mendacious law officers, and ballistic testing exp

How do we stop BS-spewing "bite mark analysis" experts, and malicious FBI crime lab "results", and habitually mendacious law officers, and ballistic testing experts, and a thousand other sorts of sounds-good BS from tricking juries? There's really nothing new here. Though many parties would prefer to pretend that our "justice" system's age-old and systematic problems didn't exist.