If you’ve been charged with an OWI, DUI, or a drunk driving offense in Indiana, you may have heard the judge mention an ignition interlock device. Maybe your license was suspended after a failed chemical test. Maybe the BMV was notified. Maybe you were told you can drive, but only with restrictions.

Now you’re asking the right question:

What is an ignition interlock device, and how is this going to affect my life?

At the Marc Lopez Law Firm, we deal with DUI and OWI cases every day. If you’re facing criminal charges and trying to protect your license, your job, and your future, here’s what you need to know.

DUI, OWI, and OVWI: Are They the Same Thing?

In Indiana, DUI (Driving Under the Influence) and OWI (Operating While Intoxicated) mean the same thing. The formal charge is usually called OVWI, Operating a Vehicle While Intoxicated.

No matter what acronym is used, the consequences can include:

• Jail time
• Fines
• Probation
• Driver’s license suspension
• SR-22 insurance requirements
• Installation of an ignition interlock device

If you’re searching for answers about drunk driving charges, you’re likely also wondering whether hiring a criminal lawyer is worth it. When your freedom and your ability to drive are on the line, the answer is simple: it matters who stands next to you in court.

What Is an Ignition Interlock Device?

An ignition interlock device (IID) is essentially a breath alcohol monitoring system installed in your vehicle.

Here’s how it works:

• The device is wired directly into your vehicle’s ignition system.
• Before your car will start, you must blow into a handheld breath monitor.
• If alcohol is detected above a preset limit, your vehicle will not start.
• A camera installed in the vehicle verifies that you are the one providing the breath sample.

This isn’t optional if the court orders it. If you want driving privileges after a DUI or OWI suspension, you may have to install one.

How Does an Ignition Interlock Work While You’re Driving?

Many people assume you only blow once to start the car. That’s not how it works.

Ignition interlock devices also require rolling retests.

That means:

• While you’re driving, the device will randomly prompt you to blow again.
• If you fail to provide a sample or register alcohol, the system records a violation.
• Depending on the situation, the device may trigger alerts or require servicing.

Yes, you may be required to provide a breath sample while actively driving. It is recommended that you safely pull over to do the test.  Yes, it is disruptive. It’s inconvenient. But if it’s court-ordered, compliance is critical.

What Happens If You Test Positive?

If alcohol is detected:

1. Your vehicle will not start (or a violation will be recorded).
2. The monitoring company is notified.
3. A report may be sent to the court or probation.
4. You may have to return for recalibration or servicing.
5. Your driving privileges could be extended or revoked.

Repeated violations can land you back in front of a judge.

When you’re dealing with a DUI case, small mistakes can become big problems.

Can Something Other Than Alcohol Trigger a Positive Result?

Yes, and this surprises people.

Ignition interlock devices are designed to detect alcohol in your breath. But they don’t know the difference between alcoholic beverages and certain common products.

We’ve seen issues caused by:

• Mouthwash
• Certain toothpastes
• Breath sprays
• Hand sanitizer
• Some medications

If you brush your teeth and immediately blow into the device, trace alcohol content can register. Mouthwash is one of the most common culprits.

That’s why understanding the rules and mechanics of your ignition interlock matters. A violation report can complicate your DUI case, even if you weren’t drinking.

How Much Does an Ignition Interlock Cost?

In Indiana, there are multiple approved vendors. Costs vary.

Typically, you’re looking at:

• Installation fees
• Monthly monitoring fees
• Calibration appointments
• Removal fees

Cheaper is not always better. Lower-cost devices sometimes lead to more vehicle issues, including battery drainage or electrical complications. Higher-quality systems may be easier on your vehicle.

When you’re already dealing with criminal defense issues, unexpected mechanical problems are the last thing you need.

Is an Ignition Interlock Required After Every DUI in Indiana?

Not always.

Whether an ignition interlock device is required depends on:

• Whether you refused a chemical test
• Your blood alcohol concentration (BAC)
• Whether this is a first-time or repeat offense
• Whether there was serious bodily injury involved
• Whether you are seeking specialized driving privileges

Some refusal suspensions limit your ability to obtain specialized driving privileges. In other cases, a judge may allow you to drive only with an ignition interlock installed.

This is where having an experienced criminal defense attorney becomes critical. The difference between a full suspension and restricted driving privileges can affect your job, your family responsibilities, and your stability.

What If I’m a CDL Holder?

If you hold a Commercial Driver’s License (CDL), the situation becomes even more serious.

CDL holders face:

• Stricter alcohol concentration limits (.04 while operating a CMV)
• Automatic disqualification periods
• Federal regulations with little flexibility

An ignition interlock device does not necessarily preserve CDL driving privileges. Federal rules often override state-level accommodations.

If driving is your livelihood, hiring a criminal lawyer immediately is not optional. It’s essential.

What Happens If I Violate Interlock Rules?

Violations can include:

• Positive alcohol readings
• Missed rolling retests
• Tampering with the device
• Attempting to have someone else blow into it

Yes, people try to game the system. We’ve seen everything from passengers attempting to blow into the device to absurd contraptions designed to simulate breath. There is even a (fictional?) news story about a man trying to use a racoon to outsmart a breathalyzer. 

The devices include cameras and reporting systems specifically to prevent that.

A violation can:

• Result in the loss of driving privileges
• Extend your interlock requirement
• Trigger probation or pre trial release violations
• Result in additional penalties
• Damage your credibility in court

When you’re facing a DUI or OWI case, credibility matters.

Why Hiring a Criminal Defense Attorney Makes a Difference

If you’ve been charged with drunk driving, your case is about more than a device in your car.

It’s about:

• Challenging the traffic stop
• Reviewing field sobriety tests
• Examining chemical test procedures
• Evaluating whether probable cause existed
• Protecting your license
• Minimizing long-term consequences

An ignition interlock requirement is just one piece of the puzzle.

At the Marc Lopez Law Firm, our criminal defense team looks at the entire picture. We focus on results. We focus on protecting your record. And we focus on helping you move forward.

Don’t Let a DUI Define Your Future

An ignition interlock device is inconvenient. A DUI conviction is life-changing.

If you’re facing OWI, DUI, or drunk driving charges in Indiana, you need more than internet answers. You need a strategy.

At the Marc Lopez Law Firm, we understand what’s at stake:

• Your license
• Your job
• Your reputation
• Your freedom

We take criminal defense seriously because your future deserves serious attention.

Call the Marc Lopez Law Firm at 463-222-0896 to schedule a consultation. Let’s talk about your options. And remember, when law enforcement starts asking questions, it’s always best to Plead the Fifth.