Being arrested on the suspicion of drunk driving is a serious matter. Those found to be intoxicated while operating a motor vehicle in Massachusetts face hefty fines, suspension of their license and jail time. Additionally, they must deal with the fallout from damage to their image and personal relationships. For these reasons, it's crucial that those accused of driving under the influence know their rights and that arresting officers follow correct procedures when making DUI arrests.
Several DUI arrests made by one police officer were recently thrown out after an investigation showed they lacked "sufficient information to prosecute". Of the 37 DUI arrests made by the police officer, 24 resulted in charges being dropped. Charges were either dropped because the drivers' blood-alcohol content was determined to be too low or due to the drivers' refusal to submit to sobriety tests.
Many of those individuals who refused to submit to a sobriety test did so after being insulted and verbally abused by the police officer in question. An investigative panel scolded the police officer for acting in a "demeaning and abrasive" manner. Likewise they chastised him for making comments to drivers that were deemed both unprofessional and inappropriate.
When making DUI arrests, the police officer relied almost solely on results of the Horizontal gaze nystagmus or HGN test which is not admissable in court.   Video footage of the police officer administering the HGN test, however, proves that he did not perform it correctly nor did he take the results of additional sobriety test measures into account. 
Based on the results of the investigation, the police officer has been demoted. He is, however, appealing to be reinstated to his previous position.