Matthew Cotter did not appear in Barnstable District Court on Monday. The Sandwich police officer arrested Friday night after his BMW went through a resident’s yard and into a parked car had been scheduled for arraignment on charges of operating under the influence of liquor, negligent operation, a marked lanes violation and driving an unregistered vehicle. Instead, according to court officials quoted by Boston 25 and the Globe, his lawyer told the court he had entered a treatment program, asked for a continuance, and got one without objection from prosecutors. The arraignment was waived and the case was continued to October 15. Cotter remains on administrative leave while his department conducts an internal investigation.
That is a routine outcome in an OUI case and an unusual one for this defendant, because of a date. As we reported Saturday, Cotter’s own department sustained a finding in September 2025 that he had been untruthful in an internal investigation, and instead of serving a five-day suspension he agreed to have it held in abeyance for one year, to be reduced to a written reprimand if he drew no further discipline. The year ran to September 15, 2026. Today. The arrest was September 11. This piece explains what waiving an arraignment for treatment means, why prosecutors agreed, what it does and does not do for the criminal case, and what it means for the abeyance clock that ran out while he was in a treatment program.
What “arraignment waived” means
An arraignment is the first court appearance, at which the charges are read, a plea of not guilty is entered, and bail and conditions are set. A defendant not in custody can, through counsel, ask that the arraignment be continued, and a defendant who has entered treatment commonly does: the court’s rules and practice favor allowing a person to begin treatment without interruption, and prosecutors rarely oppose a short continuance for a defendant who is not a flight risk and is not in custody. Cotter was released after his arrest and has been at liberty since.
Waiver of arraignment here means the formal reading and plea were dispensed with for now, not that the charges were dropped or that he has pleaded. He has not entered a plea. He is presumed innocent. The case resumes October 15, when he will either be arraigned or, if the parties have reached a disposition, proceed directly to it.
Why treatment matters to an OUI case
Massachusetts OUI law is built around treatment for first offenders. Under G.L. c. 90, § 24D, a first-offense OUI defendant may be placed on probation with a requirement to complete a state-approved alcohol education program, in exchange for which the license loss is reduced from one year to 45 to 90 days and the case may be resolved by a continuance without a finding. A defendant who has already entered a treatment program before arraignment arrives at the disposition stage with the program’s core requirement underway, and defense counsel routinely make that the first move for exactly that reason.
Nothing about the continuance decides whether Cotter is eligible for a § 24D disposition. That depends on his record, which has not been reported to include a prior OUI, and on the facts, which include a crash into a parked car on private property and a State Police field sobriety test on video. The negligent operation charge is separate and is not resolved by the alcohol program. But the sequence, treatment first, arraignment later, is the sequence of a defendant positioning for a first-offender resolution.
What it means for the abeyance
The abeyance agreement, on the POST Commission’s public record of sustained findings, required that Cotter draw no further discipline for one year from September 15, 2025. The arrest on September 11, 2026, is inside the year. But an arrest is not discipline. Discipline is what the department imposes after its own investigation, and the department has said only that he is on administrative leave pending that investigation.
The question, then, is whether the department’s internal investigation, opened before the year expired, counts as discipline within the year, or whether only a completed finding does. That depends on the wording of the abeyance agreement, which is not public, and on the town’s collective bargaining agreement. If the agreement is read to require a sustained finding within the year, the year has expired and the five-day suspension converts to a written reprimand regardless of what the investigation concludes. If it is read to be tolled by a pending investigation into conduct within the year, the suspension is back on the table, in addition to whatever discipline the OUI produces. The department has not said which reading it takes. A reasonable resident of Sandwich would ask.
The untruthfulness finding is still the point
An officer with a sustained untruthfulness finding carries it into every case in which he is a witness. Prosecutors are obligated to disclose it to defense counsel under the Commonwealth’s Brady and Giglio obligations, and defense counsel are entitled to use it to impeach him. An OUI conviction, or a continuance without a finding on an OUI, would add a second item. The internal investigation into the crash, if it examines what Cotter told responding troopers and his own department, could add a third. The criminal case is about one night. The personnel question is about whether the department can put him on a witness stand at all.
The separate incident
Investigators noted that a relative of Cotter’s arrived at the scene Friday night and that a news photographer reported being verbally and physically assaulted while recording video. That is under separate investigation, according to Boston 25. It is not part of Cotter’s case.
What to watch
October 15 in Barnstable District Court. Whether the department states publicly how it reads the abeyance. Whether the internal investigation concludes before the criminal case. And whether the Cape and Islands District Attorney treats the case as a standard first-offense OUI, which the Monday continuance suggests, or something more, given the crash.
Common questions
Was Cotter arraigned?
No. His arraignment was waived and the case continued to October 15 after his lawyer told the court he had entered a treatment program. Prosecutors did not object. He has not entered a plea and is presumed innocent.
Does entering treatment help an OUI case?
For a first offense, yes. G.L. c. 90, § 24D allows probation with an alcohol education program and a reduced license loss, and a defendant already in treatment is positioned for that disposition.
Did the abeyance year expire?
The year ran to September 15, 2026. The arrest was inside it; discipline was not imposed inside it. Whether a pending internal investigation tolls the agreement depends on its wording, which is not public.
Is he still a police officer?
Yes, on administrative leave pending the Sandwich Police Department’s internal investigation.
Court facts from Boston 25 News and the Boston Globe, September 14 and 15, 2026. Abeyance and untruthfulness findings from the POST Commission’s public list of sustained allegations, pages 224 to 225, as reported in our September 13 article. G.L. c. 90, § 24D summarized from malegislature.gov. Matthew Cotter is presumed innocent. General information about Massachusetts law, not legal advice.