The case against policeman William G. Porter deals with a question few juries have confronted: When is an officer's failure to act a crime?
Prosecutors face a difficult job proving that Porter's alleged failure to look after Freddie Gray in police custody was a criminal violation, as the standards for winning such a case are higher than in civil court, where similar cases have landed.
And the lack of precedent means fewer previous rulings to serve as a guide. So while legal experts said it's clear that police officers have a legal obligation to their prisoners, exactly what breaches of that responsibility amount to a crime remains a difficult question to answer.
David Harris, a University of Pittsburgh professor who studies policing, said American criminal laws are usually of the "thou shalt not" variety, rather than "thou shalt."
"We're pretty stingy in this country and this culture with obligating people to do stuff," Harris said.
Porter is the first of six officers to go on trial in Gray's arrest in April and death a week later. He has pleaded not guilty to charges of involuntary manslaughter, second degree assault, reckless endangerment, and misconduct in office for failing to seat-belt Gray into the back of a police transport van, where Gray suffered a severe spinal cord injury, and failing to provide medical care when he asked. All of the other officers also have pleaded not guilty.
Recent high profile cases involving police — the deaths of Michael Brown in Ferguson, Mo.; Eric Garner in New York; and Tamir Rice in Cleveland — have revolved around whether officers made the right decision to use force. Baltimore prosecutors say Gray was not the victim of a violent arrest or gunfire but of criminal negligence.
Porter's lawyers have said in court that they cannot find any other case in the country in which a police officer was criminally charged for not seat-belting a prisoner. Legal experts also said it's difficult to find criminal cases against police officers accused of inaction.
The Porter trial is scheduled to resume Monday with closing arguments. Then the jury will begin deliberating on what was going on in the mind of the rookie cop.
David Gray, a University of Maryland law professor, said the jury could decide to convict Porter of manslaughter — the most serious charge that carries a sentence of up to 10 years — based on one of two legal theories.
Under one, the jury could convict Porter if they find beyond a reasonable doubt that he knew his failure to act posed a "substantial and unjustified risk of death or severe bodily harm," the professor said.
Under another, they could convict Porter if they find that he should have known the risk and that "his failure to recognize that risk was so wanton as to represent a gross deviation from the standard of care that any reasonable officer" would have given.
Prosecutors argued the rules clearly require officers to seat-belt arrestees and to provide medical care to those in custody when they ask for it. Prosecutors said Freddie Gray asked Porter for a medic.
Porter's lawyers argued that police rarely seat-belted prisoners and that the Police Department rule — updated just weeks before Gray died — was not well-known. Porter testified in his defense that he didn't think Gray was badly hurt.
David Gray, who is no relation to Freddie Gray, said the jury will not only weigh the thorny legal issues but also Porter's state of mind.
"They're also weighing Officer Porter's credibility," he said. "A lot of what the jury will be looking at, based on everything we've seen and heard, is, does he seem like the kind of guy that would have callously decided to risk Mr. Gray's life?"
Regardless of the outcome of the criminal case, the professor said it will likely have major implications for the way police in Baltimore do their jobs.
In fact, police officers testified during the trial that they now follow the department's rules more closely.
That wasn't necessarily the case before Porter and the five other officers were charged, David Gray said. "No officer thought of those decisions as potentially exposing them to criminal liability."
In the past, allegations of injuries suffered during Baltimore police van rides have led to civil lawsuits. Harris said the standard of proof needed to find civil negligence is lower than in criminal cases, as is the degree of negligence required to hold someone responsible.
In some higher-profile cases, the family of Dondi Johnson Sr. won a $7.4 million verdict against police officers after a 2005 van ride left him a paraplegic. A year earlier, a jury awarded Jeffrey Alston $39 million when a van ride left him paralyzed from the neck down. Both amounts were later reduced.
Freddie Gray's family reached a $6.4 million out-of-court settlement with the city.
In contrast, legal experts said, it's hard to find similar criminal cases.
Philip Stinson, a professor at Bowling Green State University who maintains a database of police misconduct cases, found just two incidents among thousands he has logged between 2005 and 2011 in which police were charged with negligent homicide in a death that didn't involve a gun or an automobile crash. (More recent records were unavailable.)
The first involved officers accused of beating a suspect who later died in a jail cell, the second an officer accused of pushing someone down stairs.
Michael Serota, an attorney who works on criminal code reform, studied cases in which defendants were accused of involuntary manslaughter and depraved-heart murder, the charge faced by Officer Caesar R. Goodson Jr., the driver of the van Gray was in. Serota said he was surprised by the lack of clarity in court rulings in Maryland.
"The Maryland judiciary has, as far as I can tell, produced a surprisingly vague body of homicide law," he said.
Judges have called the state's laws "treacherously ambiguous," and "perplexing," Serota wrote in a recent law article.
In Maryland, he noted, the criminal code doesn't define manslaughter other than to say it's a felony and to outline the penalties.
Serota said unclear laws are problematic for a number of reasons, including that they make the court's work more difficult, complicate the jury's job of determining what's illegal, and diminish the public's understanding of the final verdict.
Legal experts said it could be instructive to look at other cases in which defendants are charged criminally for failing to act — such as parents accused of negligence in a child's death.
But even in cases that have some parallels to those against the six officers charged in Gray's death, appellate courts have come to very different conclusions.
In 1959, the Maryland Court of Appeals, the state's top court, overturned the conviction of two parents whose religious beliefs meant they didn't get medical treatment for a sick child. It wasn't clear, the court ruled, that by the time they ought to have intervened that the treatment would have worked.
(In the Gray case, Porter's lawyers have challenged the medical examiner's official conclusion that Gray suffered a fatal spinal injury at a point when Porter still could have intervened.)
Then in 1960, the Court of Appeals upheld the involuntary manslaughter conviction of a mother who failed to stop her boyfriend from beating her baby over many months until the baby died.
Similarly, in a pair of 1990s cases involving police who accidentally shot someone, one officer's conviction stood while another's didn't.
In the first case, Montgomery County police were pursuing a group of suspects in a stabbing. Officer Christopher Albrecht cornered the suspects and grabbed a shotgun, which he had modified to hold extra ammunition. As Albrecht confronted the suspects, the shotgun went off, killing a young woman with them.
The Court of Appeals recognized that police rules give officers latitude on when they can draw their weapons but ruled that police must still act reasonably. The court upheld the officer's conviction.
"Gross negligence in the exercise of discretion is grounds for criminal liability," the judges wrote.
Looking to that decision, Baltimore prosecutors thought they had a clear-cut case a few years later when they charged Sgt. Stephen Pagotto in an accidental shooting.
The state's attorney's office alleged that Pagotto had been criminally negligent for closing on a suspect with his gun drawn, attempting to pull the suspect from a car with one hand while improperly holding his gun. The officer argued that his actions were reasonable.
A jury convicted Pagotto of involuntary manslaughter, but the Court of Appeals threw out the verdict, finding that there was insufficient evidence. The judges ruled that reasonable officers would have acted the same way as Pagotto, so he could not be found criminally responsible.
"Each of the State's alleged violations of departmental guidelines, at best, amounted to an actionable case in civil negligence," the judges wrote.
In Porter's case, it will soon be up to the jurors to decide whether the officer is criminally responsible. Reaching a decision might not be easy, said David Gray, the Maryland law professor.
"These are the hard questions that jurors are asked to answer on behalf of society every day," he said.