Prosecution’s Guide to Impaired Driving Cases

Studies show that almost 40% of crash reports involve drunk or impaired driving. However, these cases are difficult to prove as many prosecutors are not equipped with the technical knowledge necessary to prove the elements of the offense. This makes expert testimony, crash reconstructionists, and mathematical or scientific proof and analysis essential.

In this short blog, David Serna discusses what prosecutors should know and look for when investigating a case on impaired driving.

The Phases of a Crash

A car crash occurs in three phases: pre-impact, engagement, and post-impact. These phases are further broken down into several events: point of first possible perception, point of actual perception, point of no escape, point of operator action, point of impact, post-impact trajectory, and final rest position. However, not all car crashes involve these events. The sequence of these events varies and is a case-to-case basis.

Analysis of the Evidence

The more evidence prosecution has, the fewer loopholes defense can use. This is true for all criminal cases. The defense will most likely use expert testimony to rebut the evidence presented by the prosecutor.

David Serna says that prosecutors must, before going to trial, learn some of the following crash reconstruction fundamentals: analysis of the friction marks left by tires, drag factor, crush analysis, momentum analysis, time-distance analysis, speed from event data records.

Common Defenses used in Impaired Driving

Defense usually attempts to decrease the value of the drag factor. Since the prosecutor relies heavily on mathematical values and reconstruction methods, the defense usually claims that the drag factor and the weight of the vehicle are incorrect, post-impact vehicle rotation was not taken into consideration, and the approach angles were not determined or investigated.

Prosecutors must anticipate these defenses. For more information on criminal law, defense, and prosecution follow blogs by David Serna.

3 Things to Do Before the Cross-examination of Expert Witnesses

Prosecutors should anticipate that the defense will present an expert witness, especially when the case requires medical, scientific, or technical knowledge. Conducting the cross-examination of expert witnesses will most likely be difficult since the counsels, the jury, and the judge do not necessarily possess the technical knowledge to understand every detail of expert testimony.

Today, David Serna discusses 3 ways and strategies prosecutors can use to effectively go about the cross-examination of expert witnesses.

1.       Know the common factual issues dealt with during the examination of expert witnesses

This may vary per State. It is necessary to know what issued may be raised. As a guide, Rule 702 of the Federal Rules on Evidence allows expert testimony when these three issues are raised: 1) whether the testimony is based on sufficient data or facts; 2) whether the testimony is the product of reliable methods and principles; and 3) whether the witness has applied the methods and principles reliably given the facts of the case.

David Serna says that prosecutors must prepare and pay attention if any of these three issues has been raised in the pleadings.

2.       Understand the topic or subject the expert testimony will cover

Lack of technical knowledge is indeed a limitation on the part of the prosecutor. To effectively ask questions during the cross-examination of expert witnesses, it is necessary that the prosecutor acquaints himself with basic knowledge on the subject matter.

That does not mean that he should read several books on the topic. A good source would be the State’s own expert witness. This should guide the prosecutor and trier of facts in understanding the technicalities in the expert testimony of the opponent’s witness.

3.       Know the background of the expert witness

After gathering information on the subject, the prosecutor must also know who the expert witness is. It is necessary to know if such witness is experienced, skilled, and credible. So much can be inferred from his employment history and educational background. 

Follow David Serna’s blogs for more tips on litigation, criminal law, defense, and prosecution.

Advice on Crafting Legal Briefs

A trial is a form of art. Like all kinds of performance, mastering it requires preparation. To be an effective trial lawyer, young lawyers should first know that writing persuasive legal briefs makes a sturdy foundation for trial. Today, David Serna shares his insights from over 40 years of experience as a trial lawyer.

1.       The court is your audience.

The jury and the judge are the readers of your pleadings, motions, and other documents. Making them understand and appreciate what you write and what you say are things all trial lawyers must do.

Knowing the environment where the trial takes place also matters. Visiting the courtroom will help acquaint you with the equipment it has. The equipment available is not uniform for all courts. Some have the latest technology while others don’t. Knowing what is available will help you build your presentation more efficiently.

2.       Brevity goes a long way.

The simpler, the better. David Serna believes that you are duty-bound, as a trial lawyer, to communicate with the court effectively. You must make time establishing a logical and clear argument.  Think of how to help the court understand your case. By avoiding technical and highfalutin words, you help the court grasps the facts you wish to establish, the cause of your case, and the relief your client seeks.

You are not only taking up your time. You are also taking up the time of the court. The court is burdened with a heavy workload. We don’t want to waste their time. Keep your briefs brief.

3.       Proofread.

Your first draft is rarely ever your final draft. Write and revise until you achieve the best and clearest flow for your argument. Being updated with the most recent key cases will help you, not only with advancing your client’s case, but also rebutting the opposing counsel’s defenses and objections. Be sure that the cases you cite are not incompletely quoted and to put them in the proper context.

3 Things Lawyers Must Do While Preparing for Trial

Lawyers must always thoroughly examine the evidence offered by both sides. Every piece of evidence and every testimony carries a specific objective. Lawyers must prudently consider the purpose to be carried out for each and prepare according to each set of goals.

David Serna believes these are the preliminary steps to a successful direct and cross-examination. Today, he discusses the three things all lawyers must do while preparing for trial.

1.       Keep in mind the objective you are achieving

Knowing and understanding the objective of the witness’ testimony will help you frame your questions, both for direct and cross-examination. Without definite objectives, you will only end up hurting your case.

When conducting a direct examination, for instance, the objective is to build a story and to make the jury remember that version of the story. On the other hand, when conducting a cross-examination, the counsels must be gauge whether the witness will harm or help their side of the case. If it is more harmful than helpful, the lawyer should dispense with cross-examination.

2.       Understand the challenges confronting each side of the case

Each side of the case has its strengths and weaknesses. Lawyers must always be at least one step ahead of their opponent. David Serna says that they must be able to anticipate the defenses, rebuttals, and objections that will be set up against their witnesses and evidence.

For instance, if you are the prosecutor, you must remember that the defense counsel’s tactics will involve undermining the State’s case. On the other hand, if you are the defense counsel, you must remember that strength is found in evidence that will cast doubt as to the commission of the offense charged against your client.

3.       Identify the legal parameters and limitations of each side of the case

Each side is limited by a specific set of rules. Lawyers must remember that each there are State-specific rules of evidence. Knowing what these are will help counsels craft questions for direct and cross-examination.