DNA match led to suspect in 2016 Gauthier murder case

DNA match led to suspect in 2016 Gauthier murder case

Matthew Dusseault, left and Tyler Grenon.
Grenon out on bail, awaiting trial

WOONSOCKET – As new details emerge regarding the arrest of one of the suspects in the 2016 stabbing murder of city resident Constance Gauthier, one of two suspects is out on bail following an appearance in Sixth District Court last week.

Tyler Grenon, 23, of Attleboro, Mass., was released on $50,000 bail with surety last Wednesday after state prosecutors withdrew their objections to his release. According to court documents, an individual identified as Ronald Therrien posted the required $5,000 cash the same day Grenon was granted bail before Judge Christine Jabour.

Less than a week earlier, new details emerged regarding how a second suspect, Matthew Dusseault, of 101 Cote Ave. in Woonsocket, appeared on police radar. According to an affidavit submitted to the court by Det. Thomas Gormley III on July 25, police decided in June to run an unknown DNA sample collected at the crime scene through a genealogical database, resulting in a match and leading to a break in the two-year-old case.

Gormley writes that it was Det. Anthony Conetta who had the idea to ask Parabon Nanolabs Inc., the company that processed the DNA sample, to check it against genealogy databases. The potential for law enforcement to use genealogical tools to pursue suspects through DNA matches – and the ethical questions that arise – had come to public attention in April after a genealogy website helped police track down Joseph James DeAngelo, better known as the suspected Golden State Killer.

The Woonsocket case, according to Gormley, turned up a match, indicating the DNA belonged to the father or son of Paula Gauthier, Dusseault’s mother, of no relation to the victim. Further research connected Dusseault with Grenon, said the report, which described the two as friends.

On July 17, police visited Dusseault’s home and asked him to come to the police station for questioning related to a breaking and entering, a request the affidavit says Dusseault complied with without resistance. During questioning, according to police, he made contradicting statements about what happened on March 24, 2016, admitting he was at Gauthier’s home on the day of the crime but giving different reasons for why he was at the home to begin with. Dusseault did not confess to the murder, but said he witnessed Grenon stab the victim “one or two times” and helped his friend stage the scene to look like a burglary attempt.

With the new break in the case, police issued an arrest warrant for Grenon, a neighbor who was previously brought in for questioning but released without any charges. Gormley’s comments indicate police had learned Grenon and his family had “ongoing issues” with Gauthier. Both suspects were arrested and arraigned in Sixth District Court on July 18.

Gormley’s notes were submitted to the court as part of a request for a warrant to search Dusseault’s apartment, conducted by police on July 26. According to court documents, police confiscated a large bag of assorted knives, pay stubs and several electronic devices from the Cote Avenue apartment, and were still in search of a cell phone Dusseault allegedly used to communicate with Grenon on the day of the murder.

Capt. Michael Lemoine of the Woonsocket Police Department said the items taken from Dusseault's apartment are currently undergoing analysis and declined to comment whether they had provided any new information related to the investigation.

"That usually takes some time to go through each piece and determine its evidentiary value," he said. "That remains part of the investigation."

Lemoine said he could not comment on why the judge, in consultation with the prosecutor and defense attorney, had decided to release Grenon on bail. With Dusseault's bail hearing postponed until August 29, the second suspect could also be released on bail later this month depending on the determination of the court.

In addition to a description of the arrest, Gormley's comments contain details about a tattoo Dusseault has on his right arm featuring a grim reaper and gravestone with the number “63.” Though Dusseault claimed, according to the affadavit, the number was simply one he liked, Gormley recalled that a medical examination revealed Gauthier’s body contained stab wounds numbering in the 60s and suggested the two numbers may be connected, casting further suspicion on Dusseault.

Lemoine said Woonsocket Police are continuing to investigate the case and noted the court has not yet scheduled any appearances following Dusseault's bail hearing. While Lt. Brad Scully is overseeing the continuing investigation, Lemoine said multiple officers are continuing to work on the case and have assisted throughout its two-year history.

"This has become such a vast investigation," he said. "We had numerous detectives working on various aspects of it, so it really was a team effort."

Gauthier was discovered dead in her home at 191 Fairfield Ave. on March 24, 2016. A longtime resident, the 81-year-old served on the Woonsocket Personnel Board and formerly worked as a private detective in New York. She was known for her vivacious personality and sense of adventure.