FARMINGTON — A Massachusetts man is being held without bail on a charge of murder after police say he stabbed Grace Burton, 81, on June 21 in her apartment on Fairbanks Road.

Juan A. Contreras, 27, of Waltham, was arrested Thursday in Waltham, Mass. He made his first Maine court appearance Monday morning with his attorneys, David Sanders and Christopher Berryment by his side.

Justice Michaela Murphy ordered Contreras to undergo a forensic evaluation.

Contreras will stay in jail at least until the case goes before a grand jury in January 2012. He is expected to be arraigned, if indicted, in February.

According to a police affidavit, Burton was stabbed 35 times and died as a result of the stab wounds.

Contreras was living on Pillsbury Lane, off Fairbanks Road, less than a quarter-mile from the Margaret Chase Smith Apartments on Fairbanks Road where Burton lived. Contreras is accused of cutting a screen and entering a window to Burton’s residence.

Police were able to match Contreras’ DNA found at the scene after several months of investigation. Contreras voluntarily gave a DNA sample to state police on Wednesday in Massachusetts.

Several members of Burton’s family and friends were in court during Contreras’ appearance in a bullet-proof vest Monday at Franklin County Superior Court in Farmington.

Justice Murphy said she did find probable cause to charge Contreras with murder based on an affidavit submitted by Maine State Police Detective Abbe Chabot.

If Contreras is convicted of the charge, he faces a minimum of 25 years in prison and up to life in prison, Murphy said.

According to Chabot’s affidavit, police discovered an open window at the back of Burton’s home and the cut screen.

Police collected blood samples from the ground outside the cut screen and subsequent testing revealed the samples came from a single male source and a DNA profile was developed, the affidavit said.

The DNA did not match any profiles in the database or any of several hundred samples collected from males in the Farmington area.

The affidavit states that a witness reported seeing a man of medium stature walking behind an adjacent facility shortly after the stabbing. This sighting coincided with the canine track that was conducted by Franklin County Sheriff’s Cpl. Nate Bean, who was one of the first officers on the scene.

Bean’s tracking dog, Diesel, followed the scent from Burton’s apartment to Sunny Hill Apartment Complex within minutes of Burton’s 911 call.

At a Nov. 3 meeting with State Police Detective Randall Keaten, Farmington police Sgt. Michael Adcock presented Keaten with an incident report dated July 23. In this report, a person by the name of Juan Contreras had crashed his bicycle near the intersection of Oakes Street and the Wilton Road in Farmington.

At the time, Contreras reported an address of 114 Pillsbury Lane in Farmington. In speaking with Contreras, Adcock learned that Contreras was staying at the Pillsbury address but was moving back to Massachusetts in a couple of days. No DNA sample was requested from Contreras at that time and his profile wasn’t in the system.

Keaten did additional searches of Contreras’ name, which revealed two incident reports where Contreras was a witness to different assaults. In each, Contreras was accompanied by his girlfriend, Amanda Pressey. A detective did an interview with Amanda Contreras on June 21 and she told him she was babysitting at Sunny Hill Apartment Complex.

Keaten knew from his 15 years of experience in the Farmington area that Amanda Contreras and Amanda Pressey are the same person, the affidavit states. Keaten visited Pillsbury Lane and was told the couple had been evicted a couple of months earlier.

Keaten then located and interviewed Amanda Contreras on Nov. 9. She told police that when she arrived home from babysitting in the early morning hours of June 21, her husband was heavily intoxicated and had a cut on the heel of his right hand. She confronted him about his injury and was told he injured it while whittling on a tree.

Amanda Contreras also told Keaten she had left Juan Contreras in July because he would spend his time playing video games and drinking heavily. She told police her husband was aware that she was babysitting at Sunny Hill Apartments the night Burton was killed.

In another interview with Amanda Contreras on Nov. 10, Keaten learned that when police came asking for DNA samples, Juan Contreras ran to the back bedroom and stayed there. Amanda Conteras also told police that Juan had moved back to Massachusetts about three or four weeks after Burton died.

When police interviewed Juan Contreras on Wednesday, Nov. 16, he denied being in Farmington or at Grace Burton’s apartment. He also denied knowing her.

He gave police a DNA sample.

The next day the Maine State Police Lab advised police that the DNA matched the samples taken from the window sill at Burton’s apartment and the crime scene.

Grace Burton’s daughter, Julie Shaw, said after the court proceeding Monday that the family plans to donate the $16,000 reward to the Breast Cancer Society in Brunswick in memory of her mother. The family held benefit suppers to help raise money for a reward to find her killer. Other people also donated to the cause.

NOTE: The story has been modified since it was originally published to reflect that Juan Contreras will stay in jail until January, not his attorney. It was incorrectly reported by the Sun Journal.

dperry@sunjournal.com