Chemical Test for Alcohol Unit


The Chemical Test for Alcohol Unit or CTAU manages the State of Maryland Breath Testing Program and has two primary areas of responsibility: 1) chemical testing as it relates to impaired driving and 2) training that relates to the detection, apprehension, and processing of drug and alcohol impaired drivers.  

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Chemical Testing

Chemical Testing in CTAU has three parts: 1) Breath Alcohol Testing, 2) Blood Alcohol Testing, and 3) Blood Drug Testing.  Members of the unit do not actually conduct the tests of the sample specimens but administer the programs, process the analytical paperwork associated with the testing, and maintain blood specimen test results. The blood specimens are tested by the Maryland State Police Forensic Science Division


CTAU is responsible for training all breath test operators in the state as required in the Maryland Article of Courts and Judicial Proceedings, Code of Maryland Regulations - COMAR, and Maryland Transportation Article. This training is conducted by the members of CTAU and in conjunction with allied agencies. The members of CTAU provide training to our department and allied agencies for Standardized Field Sobriety Testing, Drug Recognition Expert, Preliminary Breath Testing, and Sobriety Checkpoint Manager. Classes to become an instructor in each of those curriculums are available. Training for judges, prosecutors as well as citizen and organizational group requests for presentations related to the unit are honored whenever possible.

Statewide DUI/DWI Arrests

Annual Statewide DUI Arrest Totals:

​2014 ​2015 ​2016 ​2017 ​2018

Chemical Test for Alcohol Unit

Maryland State Police Shield 

Phone: 410-653-4315

Sergeant T.L. Aronhalt


Drug Recognition Expert Information

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