Boat driver in case over Sadie Mauro’s death in Dennis changes plea, sentenced

BARNSTABLE — A 20-year-old Medfield man accused of operating a boat while under the influence during a July 2023 crash in East Dennis that killed his 17-year-old girlfriend from Sherborn will not have to serve any jail time after pleading guilty, according to court documents filed in Barnstable District Court.

David K. Sullivan pleaded guilty on July 15 to manslaughter and possession of alcohol by a person under 21. A charge of possession of false motor vehicle registration documents was continued without a finding.

The Public Prosecution Service has dropped one charge of manslaughter by boat caused by alcohol and two charges of operating a boat under the influence of alcohol resulting in serious bodily injury.

Sullivan was driving the boat that struck a pier in Sesuit Harbor around 9 p.m. on July 21, 2023, killing Sadie Mauro, a 17-year-old lacrosse player and senior at Dover-Sherborn High School in Dover. The bottom of the boat’s hull struck a submerged rock near one of the harbor’s entrance and exit piers during low tide, said David Meier, Sullivan’s attorney.

According to the Public Prosecution Service, two other passengers were also injured.

‘Go on with your life’

Meier described the crash as an accident.

“We are grateful that the district attorney ultimately reached the same conclusion and agreed to reduce the charges to reflect the true facts. We hope that the resolution of the case will allow everyone affected by this tragedy to move on with their lives,” Meier said by phone.

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

The office of Cape and Islands District Attorney Robert Galibois had requested a two-and-a-half-year suspended sentence with five years of probation. Mauro’s family was consulted and supported the recommendation, a spokesman said.

David Sullivan gets five years probation

Judge Michael Callan ultimately sentenced Sullivan to five years’ probation.

Under special conditions of probation, he will have to perform 500 hours of community service, lose his driver’s license for 10 years, and agree not to operate a boat. He must also provide a DNA sample, abstain from alcohol, and submit to random testing for a year.

Sullivan must also complete an education program about the risk of brain disease and alcohol and continue to receive counseling from a therapist until it is no longer deemed necessary.

All six people thrown overboard

The boat was identified as a Regulator equipped with two 250-horsepower outboard motors and registered in Alabama, according to a statement from state police at the time. All six people on board were thrown overboard at the time.

Mauro’s body was recovered from the water around 11:30 p.m. by a regional dive team assisted by Dennis Fire-Rescue during a joint search off Cold Storage Beach.

Mauro had 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 someone with “a heart of gold and the sweetest spirit.”

“She had such a strong sense of self and loved adventure and anything outdoors. A hardworking student and stellar athlete, Sadie was genuinely and effortlessly kind,” Smith said.

Friends and family remember her as “a true light” who “lived each day to the fullest,” according to her obituary, and who loved “family and laughter, friends and sports, animals and the outdoors.”

“She was born with a nature and wisdom beyond her years, allowing her to live a full life that felt much longer than her time here,” her obituary reads. “She was confident, warm and empathetic in all she did, and for 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 [email protected]. Follow her on Twitter @zanerazz.

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