FARMINGTON — Police have come up empty in their search for a DNA match in the stabbing death of Grace Burton on June 21, Police Chief Jack Peck said Friday.

Of the 170 DNA samples taken, not one has matched blood left at the scene at Margaret Chase Smith Apartments where Burton lived, Peck said. The blood at the scene did not turn up on any state or national DNA crime database, he said.

Burton, 81, was stabbed multiple times in the early morning and died later that day. Police believe the perpetrator cut himself in the struggle with Burton. He left a large volume of blood at the scene, Peck said.

The suspect entered Burton’s Fairbanks Road apartment by cutting a bedroom screen. Police recently removed the front door, back window and jambs from the apartment and sent them to a special laboratory in a search for fingerprints. Peck could not comment on the results.

Town, county and state police continue a rigorous investigation that has amounted to 500 interviews, Peck said.

The State Police Crime Lab has dropped everything in the DNA section to accommodate this case, he said. Peck said he had heard that the Burton case had generated the second-largest DNA sampling in a single case in the state’s history.

Police are becoming frustrated as they search for an answer to the grisly crime, he said. “We’re doing whatever we can to bring closure for the family.”

In addition, the local department has worked to obtain money to offer a reward, Peck said. He had planned to announce the reward this coming week but later on Friday, a family member decided against it.

Family and community members have made donations but police will return the money to the donors and encourage people to give the money to the family, he said.

Farmington Police and their association have donated, as has the Maine State Police Association, he said. They also have applied for funding from the New England State Police Information Network but haven’t heard whether they will receive it, he said.

As requested, police have received numerous calls from the community reporting suspicious persons, incidents and people with cuts. Many have resulted in DNA tests.

Peck reminded residents to be vigilant and aware of their surroundings. Lock house and car doors and keep a cell phone near, he said. Call police immediately to report anything suspicious.

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