
What is criminal evidence?
Evidence is information that tends to prove or disprove a claim. The legal definition of evidence is less expansive. Evidence law concerns the reliability of the information proposed for consideration in court; as well as how police obtain the information. Some criminal evidence rules apply to criminal cases. They come from the court’s rules of evidence, statutes, case-law, and our shared cultures.

The word evidence can mean different things to different people depending upon context and usage. “Evidence” could mean different things to:
- a scientist or philosopher.
- police and private investigators: anything that could prove or disprove a theory about a potential crime or suspicion.
- a lawyer or judge: things or information legally admissible in court, in a jury trial.
When we speak of evidence in a trial, we mean legally admissible evidence. Admissible evidence is information that passes legal tests to increase reliability, fairness, and deter illegal government behavior.
Problems of proof – “May I take your order?”
Lawyers, whether defense attorneys or prosecuting attorneys, have many problems — and some of them we call problems of proof. What does that refer to? Imagine you are sure that something is true. Great. But how can you prove it, exactly? What criminal evidence can you bring into a jury trial in a court room, that will be legally admissible?
The restaurant metaphor: Imagine a restaurant, where the trial jurors come to dine. The restaurant staff must obtain the ingredients, then prepare and serve the meal. Is there a meal at all served? Does it meet the required level of excellence required by the diners? (The lawyers are metaphorically the cook and wait staff here.)
Problems of lack of proof, or low quality proofs
If criminal evidence is of low quality, a wrong verdict is likely.

We’ve all thought something true, had some evidence. And then later it turns out to be a mistake. Fortunately in our normal lives, no harm results.
“It often happens, that if a Lie be believ’d only for an Hour, it has done its Work, and there is no farther occasion for it. Falsehood flies, and the Truth comes limping after it; so that when Men come to be undeceiv’d, it is too late; the Jest is over, and the Tale has had its Effect.”
Jonathan Swift, 1710, The Examiner, No. 15
But in a jury trial, mistakes destroy lives; destroy families.
The consequences of criminal cases are severe. Therefore the laws and rules of evidence generally, are even more strict for criminal prosecutions.
Criminal evidence law more conservative than general law of evidence
For example, consider the rule against hearsay. It limits use of out of court statements offered for the truth of the matter asserted. This includes anecdotes, rumor, lack of personal knowledge. If a sworn witness testifies in court, “the other witness told me …” that would normally be inadmissible hearsay — in both civil and criminal evidence law.
The constitutional right to confront witnesses against you, however, applies only to criminal cases. A question asked of a witness that calls for hearsay, could violate the accused’s right to confrontation. But that can only happen in a criminal case.
Even if within a hearsay exception, the judge may still exclude it to protect the accused person’s right to confront.
Exculpatory evidence
Investigatory evidence that supports a possible inference of innocence is exculpatory evidence.

Police do most of the criminal investigation. So it’s important to remember that the defendant has a Constitutional right to potentially exculpatory evidence found.
The government should not hide the truth from the accused, no matter how inconvenient for the truth may be.
And at trial, the defendant has the Constitutional right to get exculpatory evidence into the record before the jury.
What is exculpatory may be in the eye of the beholder. Yet whether information is exculpatory must be from the defendant’s point of view.
Direct evidence vs. circumstantial evidence
Evidence can be direct or circumstantial.
Direct evidence supports a claim directly. It does not rely upon an inference or additional evidence to relate to the claim asserted.
Circumstantial evidence refers to a circumstance that could support one of several inferences, one being the asserted claim.

Consider this example of circumstantial evidence. You walk outside your front door early in the morning. You see the water on the grass. Does this circumstance prove that it had been raining?
Where circumstantial evidence gives rise to more than one inference and supports an inference other than guilt; then in a criminal case the court and the jury must conclude that evidence cannot support a “guilty” verdict.
Direct evidence can be unreliable too
Eyewitness testimony and confessions are two categories of types of criminal evidence that we can characterize as direct. That’s because they generally don’t depend upon some other evidence or an inference to directly relate to the dispute.
The law has been aware of the problem of unreliable confessions for thousands of years. Confessions under torture and coercion have been inadmissible due to unreliability, historically and now.
Similarly, eyewitnesses have given false testimony in countless trials and proceedings over the years, and not always intentionally.
Often the eyewitness may actually believe their own false testimony. That makes it difficult for juries and other fact-finders who may only be looking for signs of knowing deception.
Modern scientists have also discovered the many ways witnesses can be wrong. These include misidentification to perception errors to memory and reporting errors.
Confessions, Witness Statements and Hearsay
A common type of evidence in a trial is testimony about a someone’s confession, or statement.
Confessions are powerful because most assume that a person would never admit something against self-interest unless true. Upon deeper reflection, however, we know that people often confess to things they did not do.
“An innocent man, when placed by circumstances in a condition of suspicion and danger, may resort to deception in the hope of avoiding the force of such proofs.”
Justice Edward Douglass White, HICKORY v. U S, 160 U.S. 408 (1896).
And in police investigations, police pressure people to admit what the police suspect or are curious about solving. To make matters worse, some people are particularly vulnerable to making unreliable statements. These include a drunk, a person in a psychotic episode, with a head injury, a child, and so on.

Suppression of unreliable or illegal statements
Over the millennia-long development of the law, the unreliability of involuntary confessions and statements has been addressed.
And, the law has developed more recent remedies to solve problems associated with confessions and police overreaching; including the suppression of statements made in violation of Miranda rights.
Confronting hearsay at trial
Hearsay is an out-of-court statement a party offers to prove the matter the statement asserts. Under court rules of evidence hearsay is generally inadmissible — it can’t come into trial evidence, generally because it’s too unreliable.
Some hearsay is multiple hearsay. In other words, it’s hearsay within hearsay: “He said that he heard the woman there say ….” The rules of evidence include exceptions to the Rule Against Hearsay, often based upon the assumption of sufficient reliability.
But in criminal evidence law, the accused has the Right to Confront Witnesses in court. And even if admissible as an exception to the rule against hearsay; a judge can still exclude it as a Confrontation Clause violation.
“If the Government becomes a lawbreaker, it breeds contempt for law; it invites every man to become a law unto himself; it invites anarchy.”
Justice Brandeis. Olmstead v. United States, 277 U.S. 438 (1928)
Suppression of Illegally Obtained Evidence
Government run amok: We must force the government to obey the laws, since the government has so much power over all of us. If criminal evidence is from illegal government activity, a good defense lawyer will ask a judge to suppress.
Examples include evidence obtained following an illegal traffic stop or Fourth Amendment seizure of a person; an illegally prolonged detention; an illegal search.
Technology and evidence
With the development of technology, new forms of evidence become available. But it’s not all good news. It may be more of a two-steps forward, one-step back situation.
For example, consider DNA evidence. Developments in the forensic use of DNA has made it possible to use ever smaller amounts of DNA as samples; even mixed-DNA samples.
Great right? But touch DNA has increased the risk of sample contamination.
Gallagher Criminal Defense won a client’s case where the prosecutor said her DNA was on a kilo bag of cocaine. Then Thomas Gallagher uncovered that police placed the bag on the client’s dirty laundry, on a table by the washing machine. Result?

All charges dismissed, years in prison avoided, no criminal conviction record, an innocent person exonerated.
Other common types of evidence involving technology include:
- video and audio recordings,
- computer, hard drive
- cell phone and electronically stored data,
- data on the web, cell tower,
- meta tags.
Evidence law
Where does evidence law come from? Like all human laws, people develop the laws overtime. Experience, trial and error inform contemporary efforts to develop the laws to solve its problems.
The main legal authorities for law of criminal evidence are:
- the Court’s Rules of Evidence and
- Rules of Criminal Procedure;
- in state and federal statutes and constitutions; as well as
- state and federal case-law.
For example, the corroboration rule dates back thousands of years. It requires independent corroboration of a witness’s accusation before a person can possibly be guilty of a crime.
Standards of Proof
The law has different standards, or levels, of proof required for various legal purposes.

In civil cases we have the Scintilla of Evidence standard. So, a motion for summary judgment will not be granted if there is even the slightest amount of relevant evidence.
In most civil cases, the party seeking the court’s remedy has the burden of presenting evidence. The preponderance of evidence standard means the evidence makes their claim more likely than not true.
In some civil cases, the plaintiff must present evidence that is “clear and convincing” proof that their claim is true.
Beyond a reasonable doubt: But the law reserves its most strict standard of proof for criminal cases. The prosecuting attorney must present enough evidence to eliminate all doubts. The jury presumes the defendant innocent. The prosecutor must try to overcome that presumption. We can ignore unreasonable doubts, of course.
Just about every juror Thomas Gallagher has met so far has been reasonable, and not prone to unreasonable doubts. If you have a doubt, it’s reasonable.
Defense perspective
Defense Attorney Gallagher begins by mapping the known universe of possibly case-relevant information, including investigation and pretrial discovery. Then we evaluate the problems of proof related to that information.

Are there opportunities in the court process to prevent the prosecution from admitting unreliable, misleading and harmful criminal evidence? Often, there are.
We can ask the judge to suppress unreliable or illegal evidence, in a pretrial motion to suppress. A judge decides these defense motions after a Contested Omnibus Hearing.
Just before the trial we can make motions in limine to seek court rulings excluding certain criminal evidence. And we can object to improper prosecution evidence during the trial.
Just because you can, doesn’t always mean you should: Sometimes the defense may choose not to object to certain prosecution evidence even though we could, for strategic or tactical reasons.
Have a Minnesota criminal case? You can call Minneapolis Criminal Lawyer Thomas Gallagher personally, at 612 333-1500