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Former U.S. nuclear weapons titan Lawrence Livermore National Laboratory is applying its bomb know-how to help solve police cold cases.

Lawrence Livermore was established in the Cold War to advance American nuclear weapons. The lab was responsible for many pivotal advances, from thermonuclear missile warheads for submarines to developing the first high-yield warheads small enough to be carried in bulk on a ballistic missile.

Now the national lab is applying its expertise in nuclear "bomb pulse" radiocarbon analysis to help solve cold cases.

According to the Bureau of Justice Statistics, there are more than 40,000 cold cases in the United States where traditional approaches have failed to identify the victim through their remains.

A Lawrence Livermore researcher -- working with international collaborators Swedish Karolinska Institute in Sweden and the British Columbia Institute of Technology -- have created a new way to figure out ages and birth dates on those cases.

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The new approach, combining Livermore’s bomb know-how with new anthropological analysis and forensic DNA techniques, has already yielded results.

Tackling their first case, the researchers were able to identify the remains of a missing child 41 years after the body was discovered.

A child's cranium was found in a northern Canadian river bank in 1972; at the time, law enforcement believed it was from a child between the ages of seven and nine.

The case stayed cold for more than four decades until Simon Fraser University’s Centre for Forensic Research in Canada picked up the case and re-analzyed the cranium. After reviewing the skull measurements, skeletal ossification and dental formation, they decided the child was younger and died at approximately four and a half years old.

Lawrence Livermore then stepped in to help.

During the Cold War, above-ground nuclear weapons testing led to a marked escalation in global carbon-14 levels, from 1955 through 1963. While carbon-14 is in the environment naturally, the heightened levels from the bombs have been carefully tracked and recorded.

Using accelerator mass spectrometry technology, the lab boosts ions to super high  speeds to evaluate the half-life of their isotopes. Archaeologists use this sort of technology for radiocarbon dating. In this case, it registers the level of radioactive carbon-14 in the dental enamel or bones.

Dental enamel doesn’t turn over like most tissue, so carbon laid down during tooth formation acts sort of like the rings of a tree, revealing their age.

Scientists can then correlate the carbon-14 level with the records of airborne carbon-14 levels to figure out the age of the tooth and its owner to within 18 months. Other techniques are far less accurate, only narrowing age to within five or ten years.

Livermore first published their research on this pioneering enamel technique in a 2005 article in Nature.

While enamel dating won’t work with people before 1943 -- their teeth would have been formed before testing commenced in 1955 -- radiocarbon analysis can be used on bone to ascertain whether death occurred before or after 1955.

Forensic DNA analysis narrowed the list further, revealing that the child was male. Using DNA in the mitochondrial profile, they matched the young boy with a living maternal -- relative and solved the four-decade mystery.

Ballet dancer turned defense specialist Allison Barrie has traveled around the world covering the military, terrorism, weapons advancements and life on the front line. You can reach her at wargames@foxnews.com or follow her on Twitter @Allison_Barrie.