We still know very little about the investigation into the death of Freddie Gray, who died mysteriously in Baltimore police custody earlier this month. In a leaked police document, reported on Wednesday night by the Washington Post, a fellow prisoner of Gray, who was riding in the same police van, said that Gray attempted to hurt himself in the van by "banging against the walls." Gray's death was caused by a spinal cord injury. His family says that they have seen no evidence indicating that Gray caused his own death.

“We disagree with any implication that Freddie Gray severed his own spinal cord,” Jason Downs, an attorney for Gray's family, told the Washington Post. “We question the accuracy of the police reports we’ve seen thus far, including the police report that says Mr. Gray was arrested without force or incident.”

For more on the timeline leading up to Gray's death, check out our explainer.

Why is the investigation taking so long?

A couple of questions burn at the center of the city's frustration over the incident and have yet to be answered despite their seemingly straightforward disposition: what happened to Freddie Gray––and why? Gray bolted at the sight of police, was apprehended, and, half-an-hour after being stuffed into a paddy wagon, emerged with a nearly completely severed spine and a crushed voice box. And yet, the reasoning at each stage of the incident remains largely obscured to the public and some officials over two weeks later.

In that time, accusations of police cover-ups have flourished. Suspicion hasn't lessened, either, as some have pointed to a law, known as a police officer's "Bill of Rights," as a possible barrier to a fair investigation into Gray's death. It has so far prevented officials' ability to "fully engage" with the six officers involved in the initial arrest, according to Baltimore Mayor Stephanie Rawlings-Blake. "[B]ecause of our Law Enforcement Officer's Bill of Rights (LEOBOR), we have yet to fully engage those officers," she said. "I am determined to make sure that we have a full investigation and we follow all of the rules and procedures so if there is a finding of wrongdoing ... we have done everything possible to protect policy and procedures so we can hold those individuals accountable." 

According to some observers, the LEOBOR is not getting the scrutiny it deserves in cases like Gray's, where it has the potential to play a significant role in information blackouts. Maryland's version, for example, gives police officers under internal investigation for misconduct a buffer period of 10 days after the incident during which they are protected from being forced to give statements. The "cooling-off period" is intended to give officers a chance to get a lawyer, but critics say the provision allows time for officers to doctor their stories. 

Writing in the New York Times, former federal prosecutor and Georgetown law professor Paul Butler drew a comparison to a homicide investigation involving civilians, during which the first 24 hours after the crime are a crucial period for officers to interview suspects and piece together a narrative. The same would hold true for a cop involved in a homicide, he wrote, if it wasn't for Maryland's LEOBOR, which affords them extra time. "It is far from a fanciful concern that the police will take advantage of all the extra due process they get under Maryland law to concoct an alternative version of events," Butler wrote. "Indeed, in the Freddie Gray case, they have already done so."

In the police report for Gray's arrest, officers claimed that he was taken into custody "without force of incident." But in a bystander's cell phone video, which partially captured the incident, Gray can be heard yelling in pain as officers appear to handcuff him, and subsequently drag him to a police van. Butler points to the especially troubling discrepancy, since it's anyone's guess what sort of influence the official account of the arrest and the van ride fell under in the other nine days. 

It's not just Maryland.

These sorts of laws are far from unique to Maryland, however. Fourteen other states have similar LEOBORs, and as many as 11 others have considered adopting similar laws. Other states' police forces have stipulations with some of the same protections written into contracts with police unions. Proponents argue that because of their unique position that garners intense scrutiny during investigations, police officers need more time to prepare comprehensive statements.

"All this does is provide a very basic level of constitutional protections for our officer, so that they can make statements that will stand up later in court," Vince Canales, president of Maryland's Fraternal Order of Police (FOP) told the Marshall Project. 

But some protections carry the potential for abuse and sometimes seem deferential to police. According to the Marshall Project, some other common provisions of LEOBORs across the country include a ban on harassing, threatening, or promising rewards to officers under interrogation; a requirement for the department to pay salary, benefits, and legal costs for suspended officers; a statute of limitations barring discipline if 100 days have passed since an alleged incident; and, in Maryland, an officer may appeal his case to a board made up of the accused's fellow officers before any final decision is made by superiors––that board's decision is binding. 

Efforts to revise LEOBORs often face strict opposition from police unions. In fact, Baltimore Mayor Rawlings-Blake pushed for reforms in March that she hoped help speed responses from officials in holding offending officers accountable––something her team said was obstructed by the LEOBOR limitations. The case involved a 2014 video of a Baltimore officer beating a man at a bus stop, but Police Commissioner Batts said that the LEOBOR blocked immediate disciplinary action.

Given the attention Gray's case could draw to LEOBOR laws, Rawlings-Blake's comments at the time were prescient.

"It could be one incident away from being a Ferguson or a Madison or New York," she told the court. "These are very, very serious issues, and I think we have an opportunity in this time to stand together -- law enforcement, elected officials, community members -- and say that the status quo is not enough," she said. 

Canales, of the Maryland FOP fought back. "There is nothing that currently has been presented that's shown this change is actually required or needed. We stand in opposition to this bill primarily for the fact that we are nor Ferguson. We are not New York," he said at the time.