How I Research, Write, and Argue a Motion to Suppress or Dismiss

By Attorney Joe Serpa | Georgetown University Law Center | Massachusetts Criminal Defense Since 1995

A motion to suppress and a motion to dismiss are the two filings that can end a criminal case before a jury hears anything. Other motions can be important in getting to a good outcome. These two can produce an outcome, and end the case for the client before trial. That is why they are written first.

This page is about method rather than doctrine: how I find the issue, how I build the record before I file, how the motion gets written, and what I do at the hearing. The governing law on searches appears on the illegal searches and seizures page, and the grounds for dismissal appear on the page about how criminal cases get dismissed.

Where I Look First

I read the police report backward. The report is written to justify the outcome, so it presents the arrest as inevitable. Read from the end, the same document exposes a series of separate decisions, each of which needed its own justification at the moment it was made.

Each of those moments is a potential motion. Why was the car stopped. Why was anyone ordered out of it. Why was there a patfrisk. Why was the container opened. Why was the phone taken. Why was the question asked before the warning was given. An officer who has justified the last step frequently has not justified the third.

I then check the report against everything else in the file: the booking sheet, the dispatch log, the citation, the video. The suppression issue is often not in the report at all. It is in the fifteen minutes the report does not account for, or the time stamp that puts the officer somewhere else.

Building the Record Before I File

A motion to suppress is only as good as the affidavit under it, and the affidavit is where most of these motions are lost. A memorandum can argue. An affidavit has to assert facts, and those facts have to come from somewhere.

That creates the recurring problem in this practice: the facts I need are frequently known only to my client, and an affidavit from the client can be used against him. So I look for every other source first. Video. A civilian witness. The officer’s own report used against itself. A record obtained by summons. The work of assembling those sources is described in how I prepare a case for trial.

Where a client affidavit is genuinely necessary, it is drafted narrowly, to establish the one fact that gives him standing or that puts the encounter where I say it was. It does not tell his story. A defendant who explains himself in a suppression affidavit has given the Commonwealth a document to use at trial.

What a Motion to Dismiss Really Asks

Clients hear dismissal and think a judge is being asked whether the case is weak. That is not the question, and a motion written as though it were will be denied.

A court ordinarily will not inquire into the competency or sufficiency of the evidence before a grand jury. The narrow exception is whether the grand jury heard sufficient evidence to establish the identity of the accused and probable cause to arrest him. Commonwealth v. McCarthy, 385 Mass. 160, 162 to 163 (1982). A defendant may challenge sufficiency by such a motion. Commonwealth v. DiBennadetto, 436 Mass. 310, 313 (2002).

Where the grand jury received no evidence of criminality on the part of the accused, the indictment must be dismissed. Commonwealth v. Coonan, 428 Mass. 823, 825 (1999), quoting Commonwealth v. Angiulo, 415 Mass. 502, 510 (1993). Short of that, dismissal is a remedy of last resort. Commonwealth v. Troy, 405 Mass. 253 (1989).

So the motion I write does not argue that the witness is unreliable. It identifies an element and demonstrates that nothing before the grand jury addressed it. That is a much narrower claim, and it is the only version that succeeds. In the District Court the analysis runs against the four corners of the complaint application rather than a grand jury transcript, but the discipline is identical.

Operating Under the Influence

These cases have more suppression points than any other category in the District Court, because so many separate decisions are made in twenty minutes at the side of a road.

The exit order is the one most often assumed to be lawful and most often is not. An exit order during a traffic stop is justified where police are warranted in the belief that the safety of the officers or others is threatened, where there is reasonable suspicion of criminal activity, or where police are conducting a search of the vehicle on other grounds. Commonwealth v. Torres-Pagan, 484 Mass. 34, 38 (2020).

Those are three defined grounds, not a general power. So the question at the hearing is which one the officer is relying on, and what specific facts he had at that moment. An officer who answers by describing what he found afterward has answered the wrong question, and the record then shows it.

The roadside assessments and the breath test each have their own foundation requirements, and those are where an expert review pays for itself. That analysis is covered in how I use experts.

The Motion That Is Filed Too Rarely

In 2020 the Supreme Judicial Court rebuilt the framework for challenging a traffic stop as racially selective, concluding that the previous standard had placed too great an evidentiary burden on defendants. Commonwealth v. Long, 485 Mass. 711 (2020).

Under the current standard the defendant must point to specific facts from the totality of the circumstances raising a reasonable inference that the decision to stop was motivated at least in part by race or membership in another protected class. Id. at 713. Those facts may come from personal knowledge, the defendant’s own investigation, evidence obtained in discovery, and other sources. Id. at 724. A bald allegation is not enough.

If the inference is raised, the defendant is entitled to a hearing at which the Commonwealth bears the burden of rebutting it, and absent a successful rebuttal the evidence derived from the stop is suppressed. Id. at 713. The test looks to the true or subjective motivation of the officer at the time of the stop. Id. at 726 to 727.

The Commonwealth must do more than point to the validity of the traffic violation it relied on. Commonwealth v. Robinson-Van Rader, 492 Mass. 1, 17 (2023). That decision is worth reading closely, because it also confirms that no degree of racial motivation in traffic enforcement is acceptable as a matter of equal protection. Id. at 23.

These motions require data, which is why they are filed too rarely. Getting the stop history takes a summons and time, and it has to be started early.

Digital Evidence

This is the category where the law has moved furthest and where the affidavits supporting warrants have moved least. Probable cause to search or seize a cellular telephone may not be based solely on an officer’s opinion that the device is likely to contain evidence of the crime under investigation. Commonwealth v. White, 475 Mass. 583 (2016).

Police must first obtain information establishing the existence of particularized evidence related to the crime. Id., citing Commonwealth v. Dorelas, 473 Mass. 496, 502 (2016). Even where there is probable cause to suspect the defendant of the offense, that alone does not permit seizing or searching his phone. Id.

Two further points decide cases. A cell phone search warrant requires temporal limits. Commonwealth v. Snow, 486 Mass. 582, 594 (2021). And a seizure lawful when made can become unreasonable through delay: in White a sixty-eight day gap between seizure and the warrant application was held unreasonable where the Commonwealth did not show the police acted diligently.

So my reading of a phone warrant is mechanical. What particularized information tied this phone to this offense. What date range does the warrant permit. When was the device seized and when was the warrant sought. The underlying doctrine appears on the page about searches of phones and computers.

Sexual Assault Allegations

The suppression work in these cases is usually about statements rather than searches. There is often no seizure to attack and no warrant to read, and the entire case is an account given months afterward.

What there is instead is an interview, frequently conducted before any charge, sometimes at the client’s home, sometimes at the station with the door closed and the client told he is free to leave. Whether that encounter was custodial is a factual question, and the answer depends on details that are never in the report and are recoverable from the recording.

The rest of the pretrial fight in these cases is over records rather than suppression, and it runs through the summons procedure and the protocol for privileged material. Both are covered in the trial preparation page above.

Cases That Rest on a Child

Where the case is built on a young witness, the pretrial motion is about competency and about how the account was obtained. Massachusetts applies a two-part test: whether the witness has the general ability to observe, remember, and give expression to what she has seen, heard, or experienced, and whether she has understanding sufficient to comprehend the difference between truth and falsehood and the obligation to tell the truth. Commonwealth v. Trowbridge, 419 Mass. 750 (1995).

Two limits on that motion should be understood before it is filed. A trial judge has broad discretion to determine whether a competency hearing is required at all, and that determination is rarely disturbed on appeal. Commonwealth v. Allen, 40 Mass. App. Ct. 458, 461 (1996).

And Massachusetts has not adopted the New Jersey approach of a pretrial hearing into whether suggestive interviewing tainted a child’s account. The Appeals Court in Allen expressly declined to reach that question, finding the offer of proof there insufficient in any event. Id. Inconsistency in a child’s answers is ordinarily a question of credibility for the jury rather than one of competency.

What that leaves is the interview itself. How the questions were put, how many times the child was asked, who was in the room, and what the child said the first time are all cross-examination material, and they are recoverable only if the recordings and notes are obtained early.

Arguing It

A suppression hearing is not an argument, it is a cross-examination with an argument at the end. Almost all of the preparation goes into the questioning of the officer, and the questions are written in advance and asked in an order that closes the exits.

I establish what the officer knew, and when, before I ever ask what he did. An officer permitted to describe his conclusion first will supply the justification along with it. An officer taken through the timeline in sequence has to commit to what he knew at each step, and the ground for the exit order either exists at that point in the transcript or it does not.

I ask the judge for findings. Where the motion is denied and the ruling rests on a fact, the finding is what makes the issue reviewable, and a denial with no findings is much harder to do anything with later.

And I argue one ground, or two. A motion raising six theories tells the judge that none of them is strong. The one that would end the case goes first and gets the time.

After the Ruling

An allowed motion does not always end the case, and a denied one does not end the issue. Testimony given at the hearing becomes a transcript, and that transcript is useful cross-examination material, because the officer gave the answers under oath before he knew which of them would matter.

So a suppression hearing that is lost still changes the trial. That is the reason to litigate a close motion rather than trade it away, and the reason the transcript gets ordered whatever the ruling was.

Attorney Joe Serpa has practiced Massachusetts criminal defense since 1995 and tries cases in the District Courts and Superior Courts of Greater Boston. Serpa Law Office can be reached at 617.936.0201.