when state's attorney marilyn mosby stepped to the podium on may first, the city held its breath. >> the findings of our comprehensive, thorough, and independent investigation, coupled with the medical examiner's determination that mr. gray's death was a homicide which we received today, has led us to believe that we have probable cause to file criminal charges. to the people of baltimore and the demonstrators across america, i've heard your call for no justice no peace, your peace is sincerely needed as i work to deliver justice on behalf of this young man. >> ms. mosby, what do you think needs to be done to make sure what happened to freddie gray doesn't happen again? >> accountability. >> how are we going to get there? >> you're getting it today. >> mosby charged six officers, including the driver of the police van, who was arrested for 2nd degree murder. >> when the attorney gave that, i was like thank you, somebody finally said it. finally somebody is sending the police to jail for what they done. >> but charges in the freddie gray case are the exception. >> we keep pushing forw

gray dies april of 19th of last year, and the six officers are charged, the district attorney, marilyn mosby, and then we have the trial of william porter, and it ended with a hung jury, and then we have the second trial, up for murder in january, but that collapsed because the prosecution wanted to compel officer porting to testify in the case of ceasar goodson and others and the defense is saying no way. we're not having this, and the defense went to the highest court, which ruled, yes, officer porter should actually testify. what he's worried about and the team are worried about, he has signed a deal for immunity in maryland but that doesn't extend to the feds, so it's possible that whatever he says on the stand in these trials, he could be charged in a later case. and they're also very concerned that he'll be called if he appears on the stand in the other cases. he will be, no doubt about that. and in the day of twitter, people will hear about it, and it will be difficult to get an unbiased jury together when he comes back on the 6th. >> it's the sequences that's so complicated, will it

>> reporter: it's these kind of case that is has propelled the baltimore city state's corner, marilyn mosby to advocate for state house bill 218 and senate bill 235. >> these types of cases ultimately come down to credibility. >> reporter: bill supporters believe it would be most helpful for a jury to know if it isn't a defendant's first offense or if there is a documented pattern. >> one of my prosecutors has currently seven cases where this law could affect the pending cases that he has. >> there is a sense of narcissism among the offenders that these victims are just there for the taking and society must be protected from that. >> reporter: this baltimore woman was the victim of serial rapist nelson clifford who was able to convince juries that sex was consensual in her trial and the trials of two other women. his prior convictions and charges were not admissible. and this victim testified in annapolis but the bill could >> jury didn't know that he had a conviction already for rape. he was facing other trials for that. his whole history is of sexual assault. >> reporter: the bill passed

that's being prosecuted under marilyn mosby and she got in a bit of trouble when she came out and saidd justice for freddie gray. we need justice for freddie gray and many attorneys said or just justice because if justice takes us to the exoneration of the police then that's where this should go. did she misstep. >> there she said we need justice for freddie gray because justice for freddie gray because freddie gray is the one that died. justice could be whatever that leads to be. whether it ends up with criminal convictions or not. >> even an acquittal of the officers? that could be justice? >> if that is, in fact, if the officers deserve acquittal, if a jury finds them deserving acquittal, then there would be justice. but he is the only one dead. the one that you areq%Ñ lookingn for justice for was the one who was victimized. the victim here was clearly freddie gray. the question is whether -- what caused hi:op death was criminal or not. >> let me take you back to ferguson, missouri, and the case there against officer darren wilson. he shot and killed michael brown. he said it was in