I have a strong feeling the knife was unlawful to carry and she knows it, she’s between a rock and a hard place.
I hope she is under that rock with her future job aspirations.
I am not a lawyer and I have no specific information on the facts of this case. However, it appears that the prosecutor may have been caught trying to be too cute by half. Notice that she said the knife was legal "under Maryland law". That may very well be true. But the arresting office noted that the knife was illegal under a BALTIMORE ordinance, and it was for that violation that Gray was being arrested. So what the prosecutor said may have been technically correct, it was also immaterial to the specifics of this case, and certainly could not form the basis of any of the charges against the police officers.
I doubt the knife is a switchblade as defined. To be a switchblade, the button or whatever "releases" the blade has to be in the handle. I don;t recall seeing any of the common spring assist knives with a button in the handle, other than some where there is a blade lock, and on those, unlocking the blade does not result in the blade coming out (some Kershaw models).
I find it puzzling that she is averse to publishing the evidence to the public. There should be no question about what sort of knife is legal or illegal to carry. If the statute doesn't admit ascertaining that (by the general public), then the law is void for vagueness. She says it's a legal knife - so share with the public what model she finds legal (i.e., her office won't prosecute for possession).