In America we don't suffer well the pain of not getting what we want, and that includes justice. When we see something that strikes us as "wrong" or "unfair", we naturally assume it's illegal and someone will be punished.
This is not the case.
Consider, if you will, the case of John Oxendine. He had a history of abusing his son, Jeffrey; Oxendine's live-in girlfriend, Leotha Tyree, knew of this abuse and did nothing to stop it. One morning, Tyree pushed 6-year old Jeffrey into the bathtub of their apartment, resulting in internal bleeding. Over the next few hours Jeffrey felt poorly and complained of stomach pain; when Oxendine called home from work to check in, Jeffrey told him of his pain but not the genesis of it. Jeffrey received no medical attention.
The following morning, Oxendine tried to take Jeffrey. Jeffrey was sluggish and unresponsive to Oxendine's screaming, and the father then proceeded to start physically abusing the boy. Neighbors claimed to hear Jeffrey beg "No, Daddy, don't hurt me" and heard what was described as a loud thud, consistent with an incredibly hard blow to flesh.
Oxendine then went to work. Tyree noticed during the day that Jeffrey's stomach was swelling and encouraged Oxendine to take him to the doctor, but Oxendine refused. After coming home from work and seeing Jeffrey's condition, Oxendine left for a newspaper and when he returned home to read it, Tyree had prepared Jeffrey for a trip to the hospital.
Jeffrey died before he got medical treatment.
Tyree was charged with Second Degree Murder and Oxendine was charged with Manslaughter, which is legally described as reckless or wanton behavior resulting in the death of a human being.
Now think about what happened to Oxendine at trial. The way the Manslaughter statutes are written, the prosecution was unable to satisfy the burden of proof for the elements of the crime. The defense was able to get expert medical testimony that reasonably cast doubt on the assertion that Oxendine was the true factor in Jeffrey's death.
This is partly because 1) the prosecutor did not evaluate the case correctly and pushed an argument that did not legally fit the situation and 2) simply stated, as heinous as the facts of the case may be, Oxendine is not criminally liable in a way most people will find savory.
The court instead found that Oxendine's actions did not fit the definition of Manslaughter in the way the prosecutor had framed the faulty argument, and the charges were amended down to Second Degree Assault. While this sounds like a gross miscarriage of justice, note that Oxendine served THE SAME AMOUNT OF JAIL TIME under the amended charge as he would've for the initial charge. Justice?
In the view of the way our legal system works, yes. That is justice. The punishment fit the crime, in that the "crime" is defined by the statute in a certain way and certain elements must be present for there to be a "crime" at all. For example, there can be no murder without the "attendant circumstance" that the victim is a human being--if you kill an animal, it's not murder. All crimes have similar elements that make fitting an act into a criminal statute akin to finding the fitting puzzle piece.
Will this answer please everyone? Certainly not. We are disgusted when we hear Oxendine wasn't convicted of murder, when it seems so natural to us to feel that way.
Our system is, in general, a fair system. People are presumed innocent. We have rights that cannot be taken away without our permission. By and large, we live by a very fair set of rules when compared to most other countries.
But our system is not--nor will it ever be--perfect. A legislature CANNOT write an statute for any crime and expect it to perfectly fit the fact patterns of every incident that occurs. There will be loopholes. There will be people that "escape" what we feel is a fair and just result. It is the way of the world.
Despite the imperfections and how disgusted we sometimes get by reading cases similar to that of poor Jeffrey Oxendine, I've yet to see a legal system to work any better than ours.