FARMINGTON — Juan Contreras pleaded guilty Thursday morning on the fourth day of his murder trial in the death of 81-year-old Grace Burton.

The plea. accepted by judge Michaela Murphy, calls for Contreras, 28, to serve 50 years in prison. According to Assistant Attorney General Lisa Marchese, Contreras is likely to serve at least 85 percent of the sentence.

A consequence of the deal is that Contreras, who is not an American citizen, would be deported back to his native Guatemala after he serves his sentence. 

Contreras is charged with stabbing Burton 35 times at her home at Margaret Chase Smith Apartments  at 195 Fairbanks Road in Farmington on June 21, 2011.

The plea came on the fourth day of the trial in Franklin County Superior Court.

filed under: