Change of plea, sentence in Dennis boat crash that killed Dover student Sadie Mauro

BARNSTABLE — A 20-year-old Medfield man accused of operating a boat while impaired during a July 2023 crash in East Dennis that killed his 17-year-old Sherborn girlfriend will serve no jail time after pleading guilty, according to court documents filed at Barnstable Superior Court.

David K. Sullivan pleaded guilty on July 15 to boat homicide by negligence and possession of alcohol by someone under 21. A charge of possession of false Registry of Motor Vehicles documents was continued without a finding.

Prosecutors dropped one count of boat homicide caused by being under the influence of liquor and two counts of operation of a boat while under the influence of liquor causing serious bodily injury.

Sullivan drove the boat that crashed into a jetty in Sesuit Harbor around 9 p.m. on July 21, 2023, killing Sadie Mauro , a 17-year-old lacrosse player and rising senior at Dover-Sherborn High School in Dover. At low tide, the bottom of the hull of the boat hit a submerged rock near one of the harbor's entrance and exit jetties, according to David Meier, Sullivan's attorney.

Two other people on the boat were also injured, according to the district attorney's office.

'Move on with their lives'

Meier described the crash as an accident.

"We are grateful the District Attorney ultimately came to the same conclusion and agreed to reduce the charges to reflect the true facts. Our hope is that the resolution of the case will now allow everyone impacted by the tragedy to move on with their lives," said Meier by phone.

According to Meier, Sullivan was never asked to perform field sobriety tests, submit to a portable breathalyzer test or take a blood test.

Cape and Islands District Attorney Robert Galibois' office had requested a suspended sentence of two and a half years with five years of probation. Mauro's family was consulted and supported the recommendation, according to a spokesperson.

David Sullivan on probation for five years

Judge Michael Callan ultimately placed Sullivan on straight probation for five years.

Under the special conditions of probation, he will do 500 hours of community service, lose his driver's license for 10 years, and agree to not operate a boat. He must also submit a DNA sample and not consume alcohol and submit to random testing for one year.

Sullivan must also complete a Brain at Risk and alcohol education program and continue counseling with a therapist until it is no longer deemed necessary.

All six people thrown overboard

The boat was identified as a Regulator equipped with two outboard 250 horsepower engines bearing an Alabama registration, according to a state police statement at the time . All six people on board at the time were thrown overboard.

Mauro's body was pulled from the water by a regional dive team with assistance from Dennis Fire-Rescue at about 11:30 p.m. during a joint agency search off Cold Storage Beach.

Mauro was committed to Gettysburg College in Gettysburg, Pennsylvania, to play college lacrosse. When Principal John Smith announced her death in an email to the school community, he remembered her as having "a heart of gold and the sweetest spirit."

"She had such a strong sense of self and had a love for adventure and anything outdoors. A hardworking student and great athlete, Sadie was genuine and effortlessly kind," said Smith.

She is remembered by friends and family as "a true light" who "lived everyday in full," according to her obituary , and loved "family and laughter, friends and sport, animals, and the outdoors."

"She was born with a nature and wisdom beyond her years that allowed her to live a full life that felt far longer than her time here," reads her obituary. "Confident, warm, and empathetic in all she did, and to all she met, our lives will always be better and brighter because of her example."

Zane Razzaq writes about housing and real estate. Reach her at zrazzaq@capecodonline.com . Follow her on Twitter @zanerazz .

Gain access to premium Cape Cod Times content by subscribing .

This article originally appeared on Cape Cod Times: Change of plea, sentence in Dennis boat crash that killed Dover student Sadie Mauro