What is cumulative evidence in Michigan?

In Michigan, cumulative evidence is evidence that largely repeats what the jury already heard at trial. Even if it supports the defense, courts may treat it as insufficient if it does not add a materially new fact, significantly undermine key testimony, or change the overall evidentiary picture.

Why do Michigan courts deny a motion for a new trial based on cumulative evidence?

Michigan courts often deny new-trial motions when the “new” proof is viewed as additional support for an argument the jury already considered. Courts emphasize finality and require newly discovered evidence to be more than persuasive — it must be meaningfully new and make a different result probable on retrial.

Can new witnesses or new experts still be considered cumulative evidence?

Yes. If a new witness or expert essentially says the same thing as testimony presented at trial, courts may label it cumulative. To avoid that result, the new testimony must add something qualitatively different — for example, it must expose a major flaw in the prosecution’s proof or provide a substantially different explanation of what happened.

How do I show that newly discovered evidence is not cumulative in Michigan?

The strongest approach is to show that the evidence changes the evidentiary landscape. That usually means it either (1) directly impacts a core element such as identity or intent, (2) materially undermines a key prosecution witness, or (3) provides independent corroboration that was not available at trial and would likely alter how the case is decided.

What is the best way to overcome the cumulative evidence barrier in a Michigan new-trial motion?

Focus on what makes the evidence different, not just stronger. Courts respond best when the new evidence is tied to a central issue in the case and supported by reliable corroboration (records, documentation, or credible expert analysis). A well-structured motion also explains why the evidence could not have been found earlier and why it makes a different result probable.

The Hidden Role of Cumulative Evidence in Denying Motions for a New Trial in Michigan

Mark Linton
Feb 7
6 min read

Cumulative evidence shown through multiple labeled evidence exhibits in a Michigan motion for a new trial

Defendants use different strategies to challenge a conviction in Michigan. One of the most common strategies is filing a Motion for a New Trial based on newly discovered evidence. And on paper, Michigan law seems straightforward: if new evidence couldn’t have been found earlier and would probably have changed the outcome, a defendant should get another chance.

However, there’s a major barrier hidden inside that legal standard. One that derails countless motions long before they ever reach an evidentiary hearing. That barrier is the cumulative evidence doctrine. In Michigan, cumulative evidence quietly but powerfully shapes how trial courts and appellate courts evaluate whether a defendant deserves another trial.

And even when the evidence looks strong, if a judge labels it “cumulative evidence," the motion usually falls. Mark Linton is a deeply seasoned Michigan appellate attorney who knows the system's pressure points. And he has wrestled with this barrier in more courtrooms than he can count.

And here, he breaks down what cumulative evidence means under Michigan law and why courts use it to deny motions for a new trial. He also explains how several Michigan cases illustrate the problem and how to overcome the barrier.

Michigan Law Requirements for a New Trial Based on Newly Discovered Evidence

Michigan's standard for a new trial is rooted in Michigan Court Rules (MCR) 6.431(B). It's also influenced by the rigid four-part test established by the Michigan Supreme Court in the People v. Cress (2003) case. Under this rule, a court may grant a new trial if a defendant proves four things:

-The evidence is newly discovered

-The evidence isn’t cumulative

-The evidence couldn’t have been discovered with reasonable diligence

-The evidence makes a different result probable on retrial

This standard is demanding by design. And it balances the finality of convictions against the narrow possibility of correcting a miscarriage of justice. The second and fourth prongs are where most claims fall. The Michigan justice system insists that the evidence must be more than just important or persuasive. It must be fundamentally new too.

If the evidence merely repeats, reinforces, or provides a different angle on what the jury already heard, it's dismissed as cumulative. Furthermore, the judge acts as the gatekeeper of credibility. And the motion is denied if the court decides that the new evidence isn't believable or wouldn't likely tip the scales from "guilty” to "not guilty."

Michigan appellate courts are well-known for their tough standards in applying this rule. And they rarely overturn a trial judge's decision unless it "falls outside the range of principled outcomes."

What Exactly is Cumulative Evidence?

Under Michigan's legal framework, cumulative evidence is evidence that adds nothing substantively new to what was already presented at trial. There are five examples of evidence that courts typically define as cumulative evidence. The first is when additional witnesses say the same thing as the original defense witness.

The second is when more experts give opinions similar to the original expert. The third is recantations that simply restate facts already raised at trial. The fourth is affidavits that repeat the defense theory presented to the jury. And the fifth is new statements that support, but don’t expand or alter, the original statement.

Michigan courts repeatedly stress that while the evidence appears important, it's not enough unless it genuinely changes or transforms the evidentiary landscape. If the new material doesn't undercut a key prosecution witness, impeach essential testimony, or offer a substantially different version of events, it's cumulative and insufficient.

Why Courts Use the Cumulative Evidence Standard

Michigan courts use the cumulative evidence rule for three major reasons:

Protecting the finality of convictions - The justice system strongly favors finality. And courts worry that allowing repeated new-trial motions based on evidence that piles on would undermine verdicts. This is why Michigan courts often deny evidentiary hearings.

Preventing endless litigation - If every new witness or expert opinion could trigger a new trial, criminal cases would never end. And courts use the cumulative rule to filter out the evidence that simply adds more weight to an already-presented theory.

Maintaining the integrity of jury verdicts - Michigan judges avoid second-guessing juries unless the new evidence materially shifts the factual picture. And cumulative evidence, even if persuasive, doesn't usually shift that picture. This makes cumulative evidence one of the most powerful tools courts use to deny you, the defendant, a second chance.

How Michigan Courts Treat Cumulative Evidence

The People v. Bauman (1965) Case

In this case, the Michigan Supreme Court upheld the denial of a motion. This is because the defendant's proffered affidavits (challenging a rebuttal witness’s testimony on premeditation) didn't satisfy the established four-prong Cress test.

The affidavits failed primarily as they were deemed insufficient under the Cress standards. And this means they added no fresh substance beyond impeachment or support for existing proof.

The Bauman case illustrates a baseline rule. New evidence may add nothing materially new beyond corroboration or repetition of testimony already considered by the jury. And in such cases, the evidence fails the cumulative and "probably produce a different result" prongs.

The People v. Grissom (2012) case

Here, the Michigan Supreme Court emphasized the necessity for evidence that would probably change the result, not simply produce a different possibility. The Grissom case is often cited for the proposition that new evidence must be material and not merely cumulative.

To grant a new trial, the nature of the newly discovered evidence must be such that it would probably bring a different result when tried again. Thus, even powerful but redundant evidence falls short.

Grissom underscores that courts measure beyond just whether the evidence is relevant. They also check whether it significantly alters the trial's evidentiary balance.

How You Can Overcome the Cumulative Evidence Barrier

Frame the Evidence as Impairing Credibility

If a witness’s credibility is the entire foundation of the prosecution's case, frame the new evidence as attacking the reliability of the witnesses. And make sure it's so powerful that it wholly undermines the key witness. This is the witness whose testimony was the only evidence linking you, the defendant, to the crime.

Michigan Rules of Evidence (MRE) 608(a) states that courts allow you or your appeals lawyer to use evidence to show bias, interest, or credibility problems of a witness. Similarly, MRE 613(b) permits you to use prior inconsistent statements to impeach a witness.

So, highlight how the evidence fits the two rules by demonstrating three things. These are potential biases, conflicting statements, or inconsistencies that weren't fully considered during trial. When the credibility of a witness is central to the prosecution's theory, such evidence is treated as materially significant rather than repetitive.

Link Evidence to a Core Element of the Crime

For evidence to overcome the cumulative standard, it should directly address an essential element of the offense. This could be identity, intent, or the occurrence of a crime. As earlier mentioned, MCR 6.431(B) states that a new-trial motion must show that the evidence “would probably change the result.”

Similarly, Michigan Compiled Laws (MCL) 770.1 gives courts authority to grant a new trial in the interest of justice. However, courts require that the evidence pertain to core elements, not peripheral facts.

You must demonstrate that the new evidence fundamentally changes the proof regarding a central element. This way, you can prove that the new material shifts the evidentiary landscape enough to undermine confidence in the original verdict.

Support New Evidence with Corroboration

Evidence that stands alone is often dismissed as cumulative if it simply echoes trial testimony. And to overcome this, you must prove that the new information is qualitatively different.

MRE 401 and 402 establish the baseline for relevant evidence. And MRE 403 allows for the weighing of its probative value. But these rules only provide the foundation for admissibility. For a new trial motion, the evidence must also satisfy the strict procedural requirements of MCR 6.431(B).

Corroboration is the most effective way to meet this standard. And by backing a claim with independent verification, you can show that the evidence is more than just redundant. The independent verification can be done through documents, records, or expert reports that were previously unavailable.

In Michigan’s appellate world, cumulative evidence is the undertow that pulls cases under. Mark Linton, a well-refined Michigan criminal appellate advocate, knows where the current breaks. Contact Mark Linton today before your motion gets dragged the same way.