California DUI Defense, Alcohol Breath Tests, and Infrared Spectroscopy

Alcohol breath test machines have the ability to land people in jail... but they often use technology that can produce a warped result.

Our Los Angeles DUI Lawyers observe that the majority of California DUI arrests and prosecutions depend on evidence of a person's blood alcohol content (BAC). To produce this evidence, law enforcement agencies almost always use machines that convert a measurement of breath alcohol content into a BAC based on a variety of electromagnetic technologies.

The most common of these technologies is infrared spectroscopy. In its simplest terms, this process reads ultra-fine energy wavelengths that can reveal the alcohol content in a person's breath sample.

Scientists continue to indentify inherent problems with this process. First of all, infrared spectroscopy is susceptible to error because it has a proven tendency to pick up "radio frequency interference" (RFI) from surrounding electronic devices that warp results.

Second, infrared spectroscopy can only produce breath alcohol measurements that must then be enlarged in order to represent blood alcohol measurements. Because this process is based on multiple assumptions that do not always apply in particular cases, infrared spectroscopy may state that alcohol is present in a DUI suspect's system when it's really not... or it may produce a reading that is falsely high.

Bottom-line: our Los Angeles DUI Lawyers have seen these errors lead to wrongful DUI arrests and charges. However, revealing them can "torpedo" the prosecution's most important evidence. That's why we analyze every case we take on in order to discover anything that may benefit the California DUI defense we're building on a client's behalf.