PROF. JACOBSON: How do Zimmerman prosecutors prove case when key witnesses now have reasonable doubts? You know it’s a problem when MSNBC goes silent . . .

UPDATE: Reader Jerry Davis writes: “There never were any ‘key witnesses’ who supported the MSNBC version of events. Following aggressive ‘re-interviewing’ by the prosecution, some of the key witnesses have now stated they’re uncertain about some aspects of what they saw. On balance, though, their testimony hasn’t changed. The fact that’s being characterized as a weakening of the prosecution case makes it clear MSNBC’S narrative was a figment of their imagination and they’re now trying to find an excuse for their decision to distance themselves from it.”