Luis Otero, accused of killing his Groton housemate in 2010 and putting her body in a freezer, pleaded no contest Friday in New London Superior Court to murder in exchange for a 28-1/2 year prison sentence.

Otero, 51, is accused of killing Madeline J. Brisson, whom he had dated and with whom he was living at 1184 Gold Star Highway to help her cover the rent. Otero turned himself in on March 7, 2010, saying he had put a body into the freezer at that address.

The body of Brisson, 50, was frozen solid, according to police, and the state Office of the Chief Medical Examiner could not immediately determine the cause and manner of her death. The office later ruled that Brisson was a homicide victim who had died of blunt traumatic injuries and asphyxia.

Otero, who has been held in lieu of $2 million bond since his arrest, was offered last September a 27-year prison sentence in exchange for a guilty plea, but he rejected that offer.

Otero will be sentenced Nov. 9.