Discovery is the evidence exchanged through the court process. Investigation is the defense’s independent work to understand what really happened. They overlap, but they are not the same thing. A strong defense does not simply wait for the prosecutor’s file and assume the file contains the whole story.
What Criminal Discovery Can Include
New Jersey Rule 3:13-3 governs criminal discovery. Depending on the case, discovery may include police reports, witness statements, body-worn-camera recordings, photographs, laboratory reports, expert materials, electronic records, search-warrant materials, statements attributed to the defendant, and other evidence the State intends to use or that is otherwise discoverable under the Rule.
The Rule provides for substantial post-indictment discovery and also addresses pre-indictment discovery when the prosecutor makes a plea offer. It imposes obligations on both sides, so the defense can also have reciprocal disclosure duties concerning evidence it intends to use at trial.
The New Jersey Supreme Court has described the criminal discovery rules as providing broad discovery and requiring timely disclosure of relevant information. State v. Smith, 224 N.J. 36, 48 (2016). The Appellate Division has explained that discovery is intended to prevent surprise and gamesmanship and to allow meaningful preparation for trial. State v. Wyles, 462 N.J. Super. 115, 122 (App. Div. 2020).
Discovery in Municipal Court
Municipal Court has its own discovery rule, Rule 7:7-7. It is not simply a smaller version of Rule 3:13-3. A defendant who requests discovery from the municipal prosecutor is entitled to the relevant material described by the Rule, which can include police reports and notes, statements, photographs, recordings, test results, witness information, and other material relevant to the charge.
The New Jersey Supreme Court has emphasized that municipal discovery must be taken seriously. In State v. Stein, 225 N.J. 582 (2016), the Court addressed Rule 7:7-7 and explained that relevant municipal-court discovery should be produced in time for meaningful preparation. The Rule also provides remedies for noncompliance, and the proper remedy depends on the circumstances rather than automatically requiring dismissal.
Exculpatory Evidence Is Different
The prosecution’s constitutional obligation is not limited to evidence it plans to use against the defendant. Under Brady v. Maryland, the State must disclose favorable evidence that is material to guilt or punishment. That includes evidence that may directly support the defense and, in appropriate circumstances, evidence useful to impeach a prosecution witness.
New Jersey applies the familiar Brady framework. A defendant asserting a Brady violation generally must show that the prosecution suppressed evidence, the evidence was favorable to the defense, and it was material. State v. Martini, 160 N.J. 248, 268-69 (1999).
Why the Defense Conducts Its Own Investigation
A police report is a record of what police were told, observed, decided to record, and considered important. It is not an objective transcript of reality. Defense investigation may include:
- interviewing witnesses and locating people who were never interviewed by police;
- obtaining surveillance video before it is overwritten;
- preserving text messages, phone records, social-media material, or location evidence;
- examining photographs, diagrams, measurements, and timelines;
- reviewing medical, scientific, financial, or technical evidence with an appropriate expert;
- testing whether a witness’s later version matches earlier statements or objective records; and
- identifying evidence that should exist but appears to be missing.
Expert Evidence and Technical Cases
Some cases cannot be evaluated properly from police reports alone. Laboratory testing, DNA, digital forensics, accident reconstruction, medical causation, firearms evidence, financial analysis, or other technical subjects may require expert review. Rule 3:13-3 includes specific disclosure obligations relating to expert testimony so that the opposing side has a fair opportunity to prepare.
Discovery Disputes
Discovery is not always automatic or uncomplicated. Protective orders may restrict how sensitive information is disclosed or used. Parties can disagree about relevance, privilege, completeness, timing, or whether expert disclosures are adequate. Courts may be asked to resolve those disputes.
State v. Wyles illustrates that discovery duties can apply to the defense as well as the prosecution. When a defendant intends to use a statement obtained from a State witness, reciprocal-discovery rules can require disclosure before trial.
What This Stage Is Really For
The point is not to accumulate paper. It is to determine which facts are reliable, which witnesses can be tested, which evidence may be excluded, what is missing, and what the State can actually prove. The defense strategy should emerge from that work rather than be chosen before the evidence is understood.