New reports are pushing back against the criminal charges against the six police officers involved in the arrest of Freddie Gray, who suffered a fatal spinal cord injury while under police custody and died a week later.

Part of the dispute is over whether the knife in Gray's possession at the time of his arrest was legal. Last Friday, Baltimore City State's Attorney Marilyn Mosby said Gray's arrest was unlawful because the knife in his possession wasn't a switchblade, as police alleged, and was therefore legal under state law. But lawyers for two of the cops charged in the Gray case said in court filings that the 25-year-old black man was in possession of a "spring-assisted" knife, which would be illegal in Baltimore.

It would be one thing if this were only coming from the arresting officers, who obviously have a vested interest in justifying Gray's arrest to avoid criminal charges. But the knife's legality is apparently part of a disagreement between the dueling investigations — one from the state's attorney and another from the police department — into Gray's arrest and death, the Baltimore Sun's Colin Campbell reported:

While Mosby said Friday that the officers had made an illegal arrest because a knife Gray was carrying was not a "switchblade," a violation of state law, the police task force studied the knife and determined it was "spring-assisted," which does violate a Baltimore code.

We very likely won't know who's right about the knife until the case heads to court. Mosby issued a rebuttal on Tuesday, saying, "While the evidence we have obtained through our independent investigation does substantiate the elements of the charges filed, I refuse to litigate this case through the media. The evidence we have collected cannot ethically be disclosed, relayed, or released to the public before trial."

It's not immediately clear what impact this could have on the 28 criminal charges against the six police officers involved in Gray's arrest, particularly the bigger charges of second-degree murder and manslaughter. The charges may depend on all the evidence in the case, including an unreleased autopsy of Gray's body.

"I refuse to litigate this case through the media"

In another dispute, anonymous sources who reportedly reviewed the police and state's attorney investigations told CNN's Evan Perez on Thursday that some of the charges go too far — particularly the count of second-degree depraved-heart murder against Officer Caesar Goodson Jr. But CNN reported that "prosecutors must prove intent to kill" to land a conviction for the murder charge, which is false. Establishing intent to kill isn't required; instead, what needs to be proved is that a person posed a dangerous disregard for human life that created the risk of harm and led to the homicide.

"The person must show some sort of viciousness or contempt for human life. It is greater than 'negligence' where a person should have been aware of the risk, but failed to see it. The person actually created the risk of harm," Tod Burke, Radford University's associate dean and professor of criminal justice, explained in an email to Vox's Jenée Desmond-Harris. "With a 'depraved heart' it must be shown that the person committed the homicide 'wantonly.'"

Gray's death triggered tense protests and some riots in Baltimore. At one point, Mayor Stephanie Rawlings-Blake imposed a citywide 10 pm curfew, and Maryland Gov. Larry Hogan temporarily enlisted the state's National Guard to contain the violence.

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