In Virginia as in other states, the results of toxicology tests could ultimately lead to a conviction of someone accused of a DUI. However, one individual that performs such tests in another state is under investigation and has lost his job.
In one particular instance, a blood alcohol reading of one individual arrested was claimed to have been 0.24 or three times the legal limit. However, the attorney representing the individual arrested had the same blood sample independently tested. This time the results came back as 0.01. The reason why this discrepancy was so significant in that case was because the individual arrested had been charged with vehicular homicide.
The case against this individual was understandably dismissed. Authorities are now investigating the toxicologist who originally examined the blood sample to see if there is a problem with the quality of his work.
This individual had been working in the lab testing samples for approximately a year. While officials claim they never have had a problem with this individual's prior work, it certainly bears an investigation.
Authorities sometimes make mistakes when a DUI arrest is made. Sometimes police officers over step their bounds or mistakenly attribute certain behavior to alcohol or drug use. In other cases like the incident mentioned above, the evidence used in an arrest can be unreliable.
There will likely be continued controversy over blood alcohol tests taken by arresting officers. While the above incident is hopefully the exception rather than the rule, it does demonstrate that blood alcohol tests are not infallible and that results sometimes can be challenged in court by an attorney.
Source: WSMV, "TN toxicology tests under scrutiny as TBI investigates lab worker," Carley Gordon, Nov. 4, 2013