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What Types of Evidence Does Prosecution Use to Prove Intoxication in a DUI Case

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What Types of Evidence Does Prosecution Use to Prove Intoxication in a DUI Case

July 7, 2020
DUI Procedures and Testing

The prosecutor has the burden of proof presenting evidence that proves a driver was intoxicated while behind the wheel. The prosecutor will present several types of evidence to prove intoxication in a Chicago DUI case. In order for the judge to side with the prosecution in these type cases, the presented evidence must show guilt beyond a reasonable doubt.

 

These are some of the types of evidence the prosecution uses to prove intoxication in a DUI case;

 

The Official Police Report

The official police report will show the reason or reasons why the officer stopped the vehicle and tested the driver under suspicion of being under the influence. The officer may have observed driving patterns that gave them cause to pull the driver over. These driving patterns include swerving, weaving, driving with the headlights off, riding the center lane marker, or ignoring traffic signals and signs. Once the officer makes contact with the driver, they will note in their report the demeanor of the driver, and how the driver answered a number of important questions.

 

In a Chicago court, the credibility of the arresting officer is high compared to that of the suspected DUI driver. That being said, any statement the driver made will be a part of the police report and used in the court by the prosecution. Contesting these statements is difficult when working without a skilled DUI attorney who has experience contesting those statements.

 

Taking the Breathalyzer Test

 

The officer will ask the driver a number of questions before administering a breathalyzer test. Reasons for proceeding with the testing include the driver having blurred vision, slurred speech, or even smelling of alcohol. The police office doesn’t have to read the driver their Miranda rights during this questioning phase, and the driver has the right to not answer, all will be noted in the report. When the officer feels that they have reasonable cause to believe the driver is under the influence of alcohol, they will ask the driver if they consent to taking a breathalyzer test. The results of the test can be used by the prosecution in this case.

 

The driver does have the right to refuse the breathalyzer test, so the officer will inform them they will be administered a field test or be taken to the station and given a blood test. The prosecution can use all results of these tests in their case against the driver.

 

Variety of Field Tests

 

When the officer has reason to believe that the driver is drunk, they have the option to administer a number of field tests. These tests can range from asking the driver a number of questions and awaiting their response, or having the driver perform physical tests like walking a straight line or balancing on one foot. With so many field tests available, the officer will decide which test is best suited for the situation. The results of all these tests are being recorded by the dash camera on the police car and will be used by the prosecution.

 

The Chicago DUI attorney is able to view the recording and build a case against the officer as to why certain testing procedures were used and others ignored. During the trial, the DUI lawyer will put the arresting officer on the stand and inquire why one testing method was chosen over another.

 

The Blood Alcohol Test

 

Whether the driver refused to take the field test or breathalyzer, a blood test awaits them at the police station. When the driver agrees to take the blood alcohol test, the reading is considered more credible than field tests and will certainly be a part of the evidence that is presented by the prosecution. The blood alcohol test is performed at the police station by a qualified officer, and will either administer a breath or blood test to obtain how much alcohol is in the blood. Drivers with severe asthma can refuse the breath test, and will be given the blood test. If the driver refuses both tests, this will be considered a refusal by the law.

 

Refusing to take the tests is considered far worse in the eyes of the court and could result in additional penalties being added to that of the DUI. Your DUI attorney has a better chance of getting the charges lessened if they have a number to work with, a refusal makes it more challenging to defend this case successfully.

 

Your experienced DUI attorney understands precisely what evidence the prosecution will be presenting and already has started working on potential arguments in your unique case. Your lawyer is prepared to present a powerful defense that will put in question each piece of evidence in an effort to reduce the credibility of the prosecution argument.

 

 

FAQ: Evidence the Prosecution Uses to Prove Intoxication in a Chicago DUI Case

 

1) What does the prosecutor have to prove in a DUI case?

The prosecutor has the burden of proof and must present evidence showing the driver was intoxicated while driving. To win, the evidence must prove guilt beyond a reasonable doubt.

2) What types of evidence are commonly used in a Chicago DUI case?

According to the content, the prosecution may use several forms of evidence, including:

  • The official police report

  • Breathalyzer test results

  • Field sobriety test results

  • Blood alcohol test results

  • Dash camera recordings

3) How does the official police report affect a DUI case?

The official police report often includes:

  • The reason the officer stopped the vehicle

  • Observed driving behavior

  • The driver’s demeanor and responses to questions

  • Signs of impairment the officer claims to notice

The prosecution may rely heavily on this report in court.

4) What driving behaviors might lead to a DUI stop?

Officers may stop a driver if they observe behaviors such as:

  • Swerving

  • Weaving

  • Driving with headlights off

  • Riding the center lane marker

  • Ignoring traffic signs or signals

5) Can statements made to police be used against the driver?

Yes. Any statements the driver makes can be included in the police report and used as evidence by the prosecution. Contesting those statements can be difficult without an experienced DUI attorney.

6) Does the arresting officer’s credibility matter in court?

Yes. The content explains that in Chicago court, the credibility of the arresting officer is generally considered high compared to the suspected DUI driver, which can make challenging the report more difficult.

7) What happens before a breathalyzer test is given?

Before administering a breathalyzer, the officer may ask questions and look for signs of intoxication such as:

  • Blurred vision

  • Slurred speech

  • Smell of alcohol

If the officer believes there is reasonable cause, they may request a breathalyzer test.

8) Do police have to read Miranda rights before asking DUI questions?

The content states that the officer does not have to read Miranda rights during the questioning phase before breathalyzer testing. The driver also has the right not to answer, and that refusal may be noted in the report.

9) Can a driver refuse a breathalyzer test?

Yes. A driver has the right to refuse the breathalyzer test, but the officer may then administer field sobriety tests or take the driver to the station for additional testing such as a blood test.

10) What are field sobriety tests and how are they used as evidence?

Field sobriety tests may include:

  • Answering questions

  • Walking a straight line

  • Balancing on one foot

The results of these tests may be recorded (such as on a dash camera) and used by the prosecution in court.

11) Can dashcam footage be used in a DUI trial?

Yes. The content explains that field test results are often recorded by dash cameras, and this footage can be used as evidence by the prosecution.

12) What is the blood alcohol test and why is it important?

A blood alcohol test is typically performed at the police station. The content states that the results are considered more credible than field tests and are commonly used as key evidence in DUI cases.

13) What happens if a driver refuses both breath and blood tests?

Refusing both tests is considered a refusal under the law. The content explains that refusals may be viewed negatively by the court and can lead to additional penalties.

14) Is refusing chemical testing worse than taking the test?

According to the content, refusal is often viewed as worse by the court and can make the case harder to defend. The content also suggests attorneys may have a better chance reducing charges when there is a test number available rather than a refusal.

15) How can a Chicago DUI attorney challenge the prosecution’s evidence?

A DUI attorney can:

  • Review recordings and testing procedures

  • Question why certain tests were used or not used

  • Cross-examine the arresting officer in court

  • Challenge the credibility of the prosecution’s evidence

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Philadelphia

1518 Walnut Street st 808, Philadelphia, PA 19102

267-738-7766

Get Directions

Philadelphia

1518 Walnut Street st 808, Philadelphia, PA 19102

267-738-7766

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