Wednesday, February 17, 2016

How Can An Expert Assist In A DUI Case?

The defense of a drunk driving case is often multi faceted with many issues that can be pursued to develop a reasonable doubt.  Most of these issues involve science or the violation of regulatory requirements set forth by the state of California.  Indeed, DUI attorneys will tell you that defending a drunk driving case can be complex because of the science involved.  You see, in order to be effective in fighting DWI charges the lawyer must pierce the presumption that the breath test or blood test numbers from the police or lab are indeed accurate and reliable.  Here is how one well known attorney has described it:

"DUI case can be quite complex when it comes to the chemical test aspects of the defense.  Both breath and blood tests often involve very unique scientific calculations that are difficult for the laymen to understand.  This is where an expert can help. The most common experts used in a drunk driving defense are forensic toxicologists who specialize in the interpretation of an individual’s blood alcohol level at a given point in time.  You see the breath or blood test you took will only tell you the level you are at when the sample was collected.  However, what is important is what the BAC was at the time of driving This is where a toxicologist can assist the attorney.  No one’s blood alcohol level remains constant over time, it changes, either going up or down within a certain period of time.  Importantly, when a person has drank alcohol close in time to the stop, he or she will usually be rising which means their particular BAC  will be lower at the time of driving, this helps the defense. Adjudging what a true blood alcohol level is at a certain time involves complex formulas that take into account absorption rates, burn off rates, and metabolism."

In addition to issues of rising blood, many cases involve situations where a cop or other person does not follow the proper procedures when collecting a blood or breath sample.  For example, the phlebotomist may fail to properly disinfect the puncture site or the collection might violate other state regulations.  Here, as well, an expert can be used to show how the procedures were not followed and explain why the violation affects the integrity and reliability of the sample. Hiring an expert can also be helpful in raising other defences such as contamination of a breath test by mouth alcohol or people that suffer from medical conditions such as GERD.  

Thursday, February 4, 2016

Your Car's Computer Can Be Used Against You In A DUI Crash

In every DUI related car crash information about the speed of the vehicle, whether brakes were pressed prior to impact and other relevant evidence is often crucial in proving gross negligence.  In recent years the police have been getting creative in downloading data from the cars computer or SDM ( sensing diagnostic module) during their investigation. An SDM can provide important information about how the car was being driven moments prior to impact.

In one recent published opinion, People vs. Diaz, the Court noted the following:

"Every vehicle with air bags has an air bag control module that monitors a developing crash and, based on the information received, decides whether to deploy the air bags.   In addition, the module runs a diagnostic examination to make sure that its system is operating properly.   The module also has a function that records data and, after a crash, stores some of that data in the EDR, which is a component of the air bag control module.   For General Motors Corporation vehicles, this module is known as a sensing diagnostic module (SDM)․  In addition to recording such matters as the warning lamp status (which, when lighted indicates problems) and whether the driver's belt is buckled, an EDR captures information about the severity of a crash, known as the delta force or the change of speed, and the duration of the crash.   Moreover, the EDR records and stores four matters for a five-second period before a crash event—the vehicle speed, the engine revolutions per minute (RPM), the brake switch status (whether the brake has been applied), and the throttle position.“The SDM, which is controlled by a microprocessor, has multiple functions:  (1) it determines if a severe enough impact has occurred to warrant deployment of the air bag;  (2) it monitors the air bag's components;  and (3) it permanently records information.   The SDM contains software that analyzes the longitudinal deceleration of a vehicle to determine whether a deployment event has occurred based on testing that was done previously to determine what events would require protection by an air bag.   When the SDM senses an event (either a deployment event or an event that is not severe enough to require an air bag—that is, a near-deployment event), that information is recorded to the microprocessor's electrically erasable programmable read-only memory (EEPROM).   When the air bag is deployed, the SDM records the event as a ‘Code 51.’)   If the data from an EDR is properly evaluated, it can provide an impartial source of evidence for the reconstruction and biomechanics community to utilize"