physics

Katie's Law

Katie's Law is a physics topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Katie's Law rather than just read about it. In short: Katie's Law, also known as the Katie Sepich Enhanced DNA Collection Act of 2010, is a federal law to provide funding to states to implement minimum and enhanced DNA collection processes for felony arrests. The bill is named after Katie Sepich, who was brutally attacked outside of her New Mexico home in August 2003.

Key takeaways

Katie's Law belongs to physics; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Katie's Law to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Katie's Law from memory before moving on to harder problems.

Reference excerpt

Katie's Law, also known as the Katie Sepich Enhanced DNA Collection Act of 2010, is a federal law to provide funding to states to implement minimum and enhanced DNA collection processes for felony arrests. The bill is named after Katie Sepich, who was brutally attacked outside of her New Mexico home in August 2003. She was raped, strangled, her body set on fire, and abandoned at an old dump site.

Summary Katie's attacker's skin and blood were found under her fingernails. This DNA profile was sent to the Combined DNA Index System (CODIS) where officials hoped a match would be made. A DNA match identified Gabriel Adrian Avila, who had been arrested in November 2003 for aggravated burglary and was serving time in the New Mexico Corrections System since November 2004. After being confronted with his DNA evidence, Avila subsequently confessed to the murder of Sepich. The experience of Katie's parents, Jayann and Dave Sepich, in bringing Katie's killer to justice motivated them to advocate for legislation that would expand the use of DNA to arrest and convict criminals:

Jayann and Dave Sepich, Katie's parents, began researching the role of DNA in solving crimes. At first they just wanted to find and punish the person who had murdered their daughter; but as they learned more about how DNA can solve crimes, they also learned it could do so much more–it can prevent crimes and save lives. The proposed legislation encourages states to collect a sample through DNA profiling from individuals who are: arrested for, charged with or indicted for crimes involving murder, manslaughter, sexual assaults, and kidnapping or abduction. The collected samples are included in CODIS [1] which contains more than 5 million records and used by law enforcement agencies. DNA profiling is not the same as full genome sequencing and contains no genetic information. There are over 3 billion markers in the DNA molecule and only 13 of these markers go into CODIS.

Law's expansion Susana Martinez was the attorney who prosecuted and convicted the killer. While she was District Attorney, Martinez worked to pass legislation that would expand Katie's Law, requiring a DNA sample for all felony arrests. While Governor of New Mexico, Martinez signed the expansion bill into law in April 2011.

National growth On February 4, 2010, Congressman Harry Teague (D-NM) introduced H.R. 4614. The bill had 11 co-sponsors:

Rep. Gerry Connolly (D-VA) Rep. Martin Heinrich (D-NM) Rep. Tim Holden (D-PA) Rep. Steve Kagen (D-WI) Rep. Suzanne Kosmas (D-FL) Rep. Ben Ray Lujan (D-NM) Rep. Betsy Markey (D-CO) Rep. David Reichert (R-WA) Rep. Thomas J. Rooney (R-FL) Rep. Adam B. Schiff (D-CA) Rep. Anthony Weiner (D-NY) On May 18, the bill was passed in the House by a vote of 357 to 32. In the Senate side, S. 3805 was introduced by Sen. Jeff Bingaman (D-NM) on September 20, 2010, and co-sponsored by Sen. Michael Bennet (D-CO), Sen. Charles Schumer (D-NY), Sen. Tom Udall (D-NM). As of 2018, no action has been taken on the bill. 25 states have passed Katie's Law or similar programs:

Alabama Alaska Arizona Arkansas California Colorado Florida Kansas Louisiana Maryland Michigan Minnesota Mississippi Missouri New Mexico North Carolina North Dakota Ohio Rhode Island South Carolina South Dakota Tennessee Texas Utah Virginia Vermont In an interview aired on America's Most Wanted, President Obama expressed his support for the legislation, saying that "it is the right thing to do," and that "this is where the national registry becomes so important, because what you have is individual states — they may have a database, but if they're not sharing it with the state next door, you've got a guy from Illinois driving over into Indiana, and they're not talking to each other."

Criticism Some opponents argue that this policy is an invasion of privacy or a violation of civil rights. Others comment that since DNA contains sensitive genetic information it is quite different from fingerprints. A federal district court, in the United States v. Pool, upheld that the federal statute allowing collection of DNA samples prior to conviction for inclusion in the national DNA database does not represent a violation of constitutional rights. In issuing its ruling, the court specifically held that the collection does not represent a violation of Fourth Amendment rights. The court also dismissed claims of violations of Fifth and Eighth amendment rights. High courts in Maryland, and Virginia, also ruled that DNA upon arrest does not violate the Fourth Amendment. Maryland later reversed itself.

See also Adam Walsh Child Protection and Safety Act

External links DNA Saves Archived 2011-04-19 at the Wayback Machine The Surviving Parents Coalition Katie's Law John Walsh urges passage of Katie's Law

References

Worked examples

Example 1 — a first encounter with Katie's Law

Start with the simplest possible case. Write down what Katie's Law claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In physics, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Katie's Law before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Katie's Law ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Katie's Law

In research: Katie's Law appears in physics research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Katie's Law in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Katie's Law is common in secondary-school and first-year university syllabi. It links to neighbouring topics DNA profiling techniques, Law enforcement in the United States, so understanding it makes those chapters shorter.
In everyday life: Look for Katie's Law outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Katie's Law in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Katie's Law means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Katie's Law out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Katie's Law in simple terms?

Why does Katie's Law matter?

Because it connects several physics ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Katie's Law?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Katie's Law.