I thought you were concerned about "not so credible websites."
However, Snopes says the plate number DID match.
Also from the Snopes report:
WHAT'S TRUE: Police who pulled over and killed Philando Castile reported they thought he might have resembled a suspect in an armed robbery case.
Snopes says that Castile had not been named as a suspect. That is true. Police had descriptions, but not names, for the suspects in the robberies. Assuming the scanner audio is authentic, the cop used the security camera shots and descriptions as reason to pull the car over.