Ian Duncan of the Sun explores the issue:
David Harris … 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.
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Legal experts also said it’s difficult to find criminal cases against police officers accused of inaction.
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David Gray … 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.
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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.
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“The Maryland judiciary has, as far as I can tell, produced a surprisingly vague body of homicide law,” [Serota] 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.
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[In another case after a jury convicted a Maryland police officer of involuntary manslaughter], 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 [the cop], so he could not be found criminally responsible.
The judges instructions to the jury will be very important. Are those public?
My experience is in civil trials. But, I wouldn't think a criminal case is different. The court's charge to the jury is written and part of the record just like any other document filed in the case. Unless for some reason the charge is filed under seal, which I cannot imagine being the case here, it should be available to the public.
If Porter is telling the truth about all those things, the defense has a great case. But then, if the defendant's story was always true, every defense would have a great case. I see no reason to take Porter's word for anything.