How Criminal Defense Lawyers Challenge Faulty Investigations
Contents
- 1 How Criminal Defense Lawyers Challenge Faulty Investigations
- 2 Filing Motions to Suppress Evidence
- 3 Challenging the Probable Cause for Arrest
- 4 Questioning the Adequacy of the Investigation
- 5 Retaining Independent Experts
- 6 Investigating Police and Prosecutorial Misconduct
- 7 Thoroughly Interviewing Witnesses
- 8 Consulting and Retaining Investigators
- 9 Demanding Access to Physical Evidence
- 10 Scrutinizing Forensic Evidence Rigorously
- 11 Employing Jury Consultants
- 12 Seeking Experts to Challenge Forensics
- 13 Demanding Access to Lab Testing Data
- 14 Educating Judges on Forensic Science
- 15 References
How Criminal Defense Lawyers Challenge Faulty Investigations
Criminal defense lawyers have an important role in challenging faulty investigations that can lead to wrongful arrests and convictions. Here are some of the main ways they do this:
Filing Motions to Suppress Evidence
One of the most powerful tools a defense lawyer has is filing a motion to suppress evidence that was obtained illegally or in violation of a defendant’s constitutional rights. This can include evidence obtained through an unlawful search or seizure, coerced confession, or other misconduct by police. If the motion is successful, the tainted evidence cannot be used at trial.For example, if police conducted a warrantless search of a home without consent or probable cause, a defense lawyer could argue that the search violated the 4th Amendment. If the judge agrees, any evidence found in the search would be excluded. This could seriously damage the prosecution’s case.
Challenging the Probable Cause for Arrest
Police need probable cause to make an arrest, which means reasonably trustworthy facts that would lead a prudent person to believe the suspect committed a crime. Defense lawyers scrutinize the facts known to police at the time of arrest to see if they actually established probable cause.If not, the lawyer can file a motion to dismiss for lack of probable cause. This attacks the validity of the arrest itself. If successful, it could mean all evidence obtained after the arrest is excluded as “fruit of the poisonous tree.”
Questioning the Adequacy of the Investigation
Defense lawyers look critically at what steps police took—and failed to take—during an investigation. Was all relevant evidence collected and tested? Were other obvious leads ignored? Did detectives adequately pursue alternative suspects?If glaring investigative flaws are uncovered, the defense lawyer can raise reasonable doubt about the strength of the state’s case. This is especially powerful during cross-examination of the lead detective at trial.
Retaining Independent Experts
When scientific evidence like DNA or ballistics is central to the case, defense lawyers often hire independent experts to critically review the analysis done by police labs. Technical mistakes in testing procedures or erroneous expert conclusions can be exposed.If flaws are found, the defense can ask the court to exclude the evidence or at least mitigate its impact. Retaining reputable experts signals the defense is taking the forensics seriously.
Investigating Police and Prosecutorial Misconduct
Defense lawyers have an obligation to investigate any signs of misconduct, such as witness coaching, evidence tampering, or concealing exculpatory evidence. While rare, documented misconduct can lead to dismissal of charges or other sanctions against the state.Even subtle misconduct like overstating forensic conclusions can be used to undermine credibility of the state’s witnesses.
Thoroughly Interviewing Witnesses
The defense must independently interview all major witnesses and document any inconsistencies with police reports or testimony. Eyewitnesses are fallible, memories fade, and stories evolve over time. Impeaching witnesses with prior inconsistent statements is a key tactic.Finding witnesses neglected by police—like additional alibi witnesses—can provide ammunition to argue the investigation was incomplete or biased.
Consulting and Retaining Investigators
Few defense lawyers have the time or expertise to fully recreate complex crime scene investigations or re-trace witnesses’ statements. Hiring trained criminal defense investigators levels the playing field against the police.Investigators may uncover additional suspects, find exculpatory evidence, or identify logical gaps in the state’s version of events. Their findings can be pivotal in undermining flawed police work.
Demanding Access to Physical Evidence
The defense must independently examine all available physical evidence, not just rely on police reports. This includes viewing crime scene photos, analyzing forensic lab results, or even hiring experts to re-test DNA samples or fingerprint evidence when possible.Hands-on access prevents evidence from being exaggerated or misinterpreted by the prosecution. It also preserves the right to challenge admissibility of evidence at trial.
Scrutinizing Forensic Evidence Rigorously
With the tremendous weight juries give scientific evidence, defense lawyers must rigorously scrutinize the methodologies used and the qualifications of forensic analysts. Are there accepted standards for testing this type of evidence? What are the error rates? Is the analyst overstating conclusions?Judges are increasingly demanding that forensic results meet basic reliability and relevance standards before being admitted. Defense challenges ensure junk science is kept out.
Employing Jury Consultants
For complex trials involving disputed forensic evidence, some defense lawyers hire jury consultants. They assess whether jurors are likely to comprehend the scientific nuances, or if they will give undue weight to evidence they do not fully understand.Consultants help ensure the jury pool is not inherently biased against technical defense theories before trial.
Seeking Experts to Challenge Forensics
In cases relying heavily on forensic evidence, the defense may retain experts in the relevant discipline to re-examine the evidence firsthand and identify limitations of the methodology used by police. Finding flaws in the state’s expert testimony can undermine its persuasiveness.Highly qualified defense experts can also educate the jury on the technical complexities and risks of error associated with forensic evidence. Their testimony provides crucial context.
Demanding Access to Lab Testing Data
Defense lawyers often have to fight for access to all the data underlying forensic testing results, including chain of custody records, instrument maintenance logs, analyst bench notes, validation studies, and proficiency tests.Such data can reveal procedural flaws, reliability issues, and analyst errors that compromise the accuracy of test results. Full data access is essential for independent defense experts.
Educating Judges on Forensic Science
Many judges do not have scientific backgrounds and struggle to fulfill their gatekeeping role in assessing reliability of forensic evidence. Defense lawyers have a duty to educate judges on the limitations of different forensic disciplines that lack rigorous scientific validation.Judges so informed will be less likely to admit questionable forensic evidence that could mislead the jury.The bottom line is diligent defense investigation and litigation can expose shoddy police work, correct the record, and prevent tragic outcomes like wrongful convictions. As long as humans are involved, no investigation will be perfect. By challenging deficiencies, defense lawyers uphold truth, justice, and fairness under the law.
References
https://www.law.berkeley.edu/files/thurs_sci_forensics.pdf
https://www.innocenceproject.org/pretrial-motions-and-hearings-faqs/