How Did The US Justice System Lose Sight of Intent?

Your question seems focused on the intent behind the passage of a particular law. The difficulty with the "intent" of a law is how do you define it? Often times laws are passed and nowhere does it say "this law is passed for the specific purpose of doing X, or preventing Y." Even in situations where there is a passage in the law that says "this law's intent is to combat Z," that may not be trustworthy because the politicians that draft such language know that a court will look to that passage for the "intent." And, as society changes at what point do you no longer consider the intent of a law? For example, think of the "Jim Crow laws" in the US.

The intent of a law is rarely concrete, but what is concrete (basically) is the letter of the law. Now even a textualist like Antonin Scalia will try to figure out the intent if the letter of the law leads to an absurd result.

The point is that the intent of the law often looks clear to one person, but many times another person can marshal an equally strong argument that the intent is different in some way, so then you are left with the question of who wins.

Furthermore, you cited one case which definitely looks absurd on its face, but is not necessarily representative of the entire US legal system.

You are asking a slightly biased question, by presuming that the UK justice system (unlike the US) is very fair and looks at intent and the poor old US has lost it's way and is now silly.

You are wrong, the UK justice system can be just as stupid aswell, just look at the ambulance driver convicted of speeding while transporting a liver for transplant ( http://www.bbc.co.uk/news/uk-scotland-edinburgh-east-fife-17842413 )

(There are other example of extremely harsh sentances after the recent london riots for trivial things)

Intent actually is a very important principle in US law.

However, what you are linking to is not the actions of a judge, but the actions of elected District Attorneys. That is sort of a low-rung political position, that is often used as a springboard for higher office. The trick is to get your name in the news a lot, and for doing that nothing serves better than bringing controversial high-profile cases.

Few things in the USA are more controversial than abortion. The anti-abortion folks are a majority in some states, and exert political influence far beyond their numbers even when they are not, due to how motivated they are. Being seen as their political ally (particularly in conservative states like Indiana) can really jump-start a political career.

One of the latest tactics from the anti-abortion folks has been to use the legal system to try to push the concept that a fetus is a full-fledged US citizen. You can't (yet) do that for outright abortion, but you can often get sympathetic ears for other circumstances where a fetus is lost (eg: murder or abuse of the mother). This is just the next step in that process.

When it comes to a judge, I suspect you will find most of these cases losing (if not getting thrown out outright). However, in most municipalities judges are elected too...

Bei Bei Shuai was charged under a state law similar to one passed in 37 other states and a Federal law signed by President George W. Bush, codified at 18 U.S.C. § 1841, that makes it a crime to cause the death of fetus. Exceptions are provided for legal abortions, medical treatments, and so on. Although seen as an anti-abortion bill, the legislation would have the more primary impact of permitting a charge of two counts of murder when an assailant kills a pregnant woman. Did the drafters of the law intend to prevent a woman from causing the death of her child by killing herself? I think if you would have asked the Congressmen who voted for the bill, they would mostly say "yes." Their goal was to save the lives of babies, no matter what. So, I think that this is not a good case for you to say that the U.S. justice system has lost sight of intent.

The Courts, actually, very much focus on the intent behind the language of a statute or the Constitution. As the legal reference book, Corpus Juris Secundum (CJS) says in its chapter on Constitutional law:

In construing a constitutional provision, the function of the court is to ascertain and give effect to the intent and purpose of the framers and the people who adopted it.
When interpreting a constitutional provision, a court examines its purpose and intent, and constitutional provisions should be construed in consonance with the objects and purposes in contemplation at the time of their adoption. It is a rule of construction applicable to all constitutions that they are to be construed so as to promote the objects for which they were framed and adopted. It is the duty of a court to interpret the various provisions of a constitution to carry out the spirit of that instrument.

16 C.J.S. Constitutional Law § 58 (footnotes omitted).

In the recent U.S. Supreme Court gun control case of District of Columbia v. Heller, 554 U.S. 570, 634-35 (2008), Justice Scalia explained "Constitutional rights are enshrined with the scope they were understood to have when the people adopted them, whether or not future legislatures or (yes) even future judges think that scope too broad."

Similarly, U.S. courts look closely to the intent of Congress unless the statute is clear on its face. Using Colorado as an example, one court summarized this rule:

In construing a statute, Colorado courts “aim to ascertain and give effect to the intent of the General Assembly”.... “If the language in the statute is clear and the intent of the General Assembly may be discerned with reasonable certainty, it is not necessary to resort to other rules of statutory interpretation”.... “If, however, the language of the statute is ambiguous, or in conflict with other provisions, [courts] then look to legislative history, prior law, the consequences of a given construction, and the goal of the statutory scheme, to ascertain the correct meaning of a statute.”

Toy v. American Family Mutual Insurance Company, 2014 WL 321213 (D. Colo. January 29, 2014) (footnotes omitted).

As Sutherland's Statutory Construction explains the general rule followed by all American courts:

Courts look to a statute's contemporary history and historical background as aids to interpretation. These aids illuminate the circumstances under which an act was passed, the mischief at which it was aimed, and the statute's “object” or “purpose.” This form of extrinsic evidence about legislative intent may include court opinions, where a statute is an attempt to codify the rationales of relevant judicial decisions. As with all legislative history, courts generally turn to a law's pre-enactment history to discover its purpose, or object, or the mischief at which it was aimed, when the statute's language is inadequate to reveal legislative intent.

2A Southerland § 48.3 (footnotes omitted).

Based on the foregoing, I believe that you have misinterpreted Ms. Shiao's prosecution as a failure to understand legislative intent, or to understand it as a move away by courts to follow the intent of legislators in intepreting statutes.

I can't say that I agree with the statement that the US Justice System has lost sight of intent; We have the In Re Gault case where the law said that a boy would go to a reform school for several years for a crime that a grown man would get fined several dollars and spend a month or two in jail (charges of the top of my head.) You might quote Miranda VS Arizona as a case where the law was followed against common scene, but I'd argue that it was totally within the intent of the law; the constitution and all (well, most) of it's amendments are there to help secure rights. One of them, the 5th amendment states, one can only be tried with due proses of law, your "Miranda Rights" must be told to you at your arrest. If Miranda was charged, it would set a precedent saying that if the government wanted to frame someone, all they had to do was tell them fase rights or none at all, and try them with the evidence. The intent of American law was not to catch the bad-guys, but rather to let the good guys go. (A person can't face double jeopardy) This is a reason why many of the cases that have been ruled upon's rule seem so strange. Now that I've finished my little (long really) segway off topic, I will resume answering the question. In this case, I'd agree that the word of law as followed rather than the intent, but this is why we have many levels of law in the US. Though all states have a different justice system (needs confirmation), all have the many levels, and all allow you to challenge the ruling all the way up to the state Supreme Court. Even though this case was judged by the word of the law, some where up there someone will judge it (probably) by the intent of the law.