FARMINGTON — The former father-in-law of the man on trial this week for the murder of Grace Burton testified today that he became suspicious of the man he lived with in Farmington after seeing a cut on his hand.

Vern Pressey, 47, now of Pittsfield, said as he heard more about the stabbing death of Burton, 81, he decided to confront his son-in-law, Juan Contreras.

“We wondered if he was telling us the truth about how he cut his hand; if it was true,” Vern Pressy told Justice Michaela Murphy in the jury-waived trial. “I went back to the apartment and straight out asked him if he killed Grace Burton. He lied to me and said  no.”

Contreras, 27, has acknowledged being inside Burton’s apartment June 21, 2011, but never described how or why the woman was stabbed 35 times, She died hours later in a Lewiston hospital. Contreras told his wife and her father he had cut his hand while whittling, a pass time he enjoyed.

The defense team of David Sanders and Chris Berryment are trying to show that Contreras had been given a marijuana cigarette laced with a mind-altering drug and did not know what he was doing.