27 Nov 23

How Criminal Defense Attorneys Investigate Cases in New Jersey

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Last Updated on: 5th December 2023, 08:36 pm


How Criminal Defense Attorneys Investigate Cases in New Jersey

In New Jersey, criminal defense attorneys have a critical role in investigating cases on behalf of their clients. Thorough investigation by the defense is crucial to ensure a fair trial and protect the constitutional rights of the accused.

The Role of Investigation in Criminal Defense

After being retained, one of the first steps a New Jersey criminal defense attorney will take is to conduct an independent investigation of the facts. This serves several key purposes:

  • Uncovering exculpatory evidence that undermines the prosecution’s case
  • Identifying weaknesses or flaws in the state’s evidence
  • Locating witnesses and uncovering alternate theories about what occurred
  • Verifying the strength of the prosecution’s case before deciding whether to take a plea deal

Unlike the police and prosecution who focus solely on building a case against the defendant, the criminal defense lawyer has an ethical obligation to act as an advocate and represent the defendant’s interests. This makes independent investigation by the defense team essential.

Thorough investigation by the defense can also pressure the prosecution to dismiss weak cases by exposing flaws in their evidence early on. At a minimum, it allows the defense attorney to vigorously cross-examine the state’s witnesses and challenge their version of events at trial.

Common Investigative Techniques Used by NJ Criminal Defense Attorneys

New Jersey criminal defense attorneys have a variety of investigative techniques at their disposal to dig into the facts of a case:

Interviewing the Client

One of the first steps a defense attorney will take is conducting an in-depth interview of the client to get their side of the story. This allows the attorney to identify potential defenses, such as self-defense or alibi, that can then be investigated further. The client interview also helps locate supporting witnesses.

Visiting the Crime Scene

Experienced New Jersey criminal defense attorneys will often visit the scene of an alleged crime themselves. This allows them to verify distances, lines of sight, lighting conditions and other physical evidence. If there are discrepancies between the state’s version of events and the actual crime scene, those can be powerful arguments for the defense.

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Interviewing Witnesses

Locating and interviewing both prosecution and defense witnesses is a core part of building an effective defense. Skilled NJ defense attorneys know how to question witnesses in ways that bring out important details the police may have missed. Witness interviews can uncover alternate suspects, expose contradictions in witness statements, or reveal flaws in police procedures.

Collecting Physical Evidence

Defense investigators may photograph and measure crime scenes, just like police. They can also hire forensic experts to re-examine physical evidence using more sophisticated techniques than basic police lab tests. This can uncover exculpatory evidence like DNA from alternate suspects. Independent forensic analysis may also discredit unreliable techniques used by police.

Subpoenaing Documents

NJ criminal defense attorneys can issue subpoenas to obtain documents that may aid the defense, such as medical records, phone records, employment files, or receipts showing the defendant was elsewhere at the time of the crime. These records are not necessarily evidence the prosecution would collect in building their case against the defendant.

Consulting Experts

Retaining independent forensic experts, psychologists, and other specialists to analyze the evidence can provide information the police investigation missed. Defense experts may offer alternate interpretations of physical evidence, undermine prosecution expert witnesses, or explain a defendant’s mental state or intent at the time of the alleged crime.

Conducting Background Checks

Thoroughly investigating the background of both the defendant and any witnesses is also standard practice. This can uncover prior convictions that could impeach a witness’s credibility or psychiatric issues that cast doubt on their reliability. For the defendant, evidence of good character can raise reasonable doubt and is an important mitigating factor at sentencing if convicted.

Why Independent Investigation is Vital for an Effective Criminal Defense

The fact is, police and prosecutors face heavy caseloads and limited resources. Their investigations necessarily focus on building a case against the defendant, not uncovering potentially exculpatory evidence. This makes independent investigation by the defense team absolutely essential.

Without conducting their own investigation, defense attorneys would be forced to rely solely on the information gathered by police and prosecutors. But the United States Supreme Court has made clear that the prosecution has no obligation to actively seek out evidence favorable to the defense during an investigation. Failing to independently examine the facts and challenge the state’s evidence can lead to wrongful convictions.

Additionally, information flows in one direction in the criminal justice system, from police to prosecutors. So even if exculpatory evidence exists, the prosecution may never see it if the police investigation was incomplete. Thorough investigation by the defense helps correct these systemic imbalances and protects the constitutional right to present a complete defense.

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Finally, early investigative work is critical because it allows the defense attorney to make informed strategic decisions about how to proceed in the case. The attorney can provide better advice to their client regarding whether to take a plea bargain or proceed to trial once the relative strengths and weaknesses of the evidence are known.

How Criminal Defense Attorneys Put Their Investigative Findings to Use

The fruits of a defense team’s investigative efforts can be used in various ways to advocate for the client:

  • Filing motions to suppress evidence – If there are Constitutional violations or other procedural defects in how evidence was collected, defense attorneys can file motions asking the court to suppress that tainted evidence so it cannot be used at trial.
  • Plea negotiations – Demonstrating weaknesses in the prosecutor’s case may lead to more favorable plea offers or even persuade the prosecution to drop charges.
  • Cross-examination of witnesses – Thorough investigation allows the defense attorney to rigorously question the credibility and reliability of prosecution witnesses on the stand.
  • Presenting affirmative defenses – Evidence gathered can be used to establish justification defenses like self-defense that excuse otherwise illegal conduct by the defendant.
  • Calling defense witnesses – Investigative findings can lead to important witnesses for the defense who provide alternate theories, alibis, or testimony impeaching the credibility of prosecution witnesses.
  • Sentencing mitigation – If a conviction occurs, investigation into the defendant’s background and character can persuade the judge to impose a lighter sentence.


Thorough, independent investigation by New Jersey criminal defense attorneys levels the playing field and acts as an important check on the power of the government in the criminal justice system. While police and prosecutors focus on building a case against the accused, the defense lawyer has an ethical duty to act as a zealous advocate for their client. Investigating the facts from the defendant’s perspective safeguards Constitutional rights that protect all citizens from overreach by the state.