"Jared Remy pleaded guilty to first-degree murder and related assault charges. A sentence of life without parole will be automatic.
"The stabbing was witnessed by a neighbor and took place with the couple's five-year-old daughter was in the home. The surprise plea spares the girl -- whose name is tattooed on Jared Remy's neck -- from possibly having to testify against her father.
"Martel, whose parents were in the courtroom today and who now have physical custody of the child, was just 27 years old and had filed a restraining order against Jared Remy for assaulting her days before her death. His guilty plea today includes that attack.
"Remy, 35, a former security guard for the Red Sox, had a long history of arrests for domestic assaults of a string of girlfriends. He had been scheduled to go on trial Oct. 7 in Middlesex Superior Court in Woburn.
"In addition to murder, he pleaded guilty to assault and battery with a knife, assault and violation of a restraining order."
In a separate update, Jared Remy's parents expressed grief over Martel's slaying. In addition, Jared Remy also admitted to the judge he killed his girlfriend, per The Boston Herald's Laurel J. Sweet.
"Just hours after his son admitted to first-degree murder, Red Sox color commentator Jerry Remy and his wife released a statement saying 'no words can express the sorrow' over the slaying of Jennifer Martel.
"They did not address the sentence of life without parole their 35-year-old son was automatically given with his sudden change of plea.
"'We continue to be heartbroken over Jenn's death. That will never change,' the couple said through their son's attorney, Edward P. Ryan, Jr. 'No words can express the sorrow we feel for the Martel family. We are now focusing our attention on our grandchildren and doing what is best for them.'
"Jared Remy pleaded guilty today to killing his 27-year-old girlfriend -- a slaying that took place Aug. 15 as his daughter, Arianna Nicole, now 5, was in the Waltham home.
"'I am here today not for a deal, but to take responsibility for what I have done. I would like you to know that I always told Jen she could leave, but don't threaten me with my daughter.'
"'That night, Jen had a knife in her hand and threatened me with my daughter. So I killed her,' Jared Remy told Middlesex Superior Court Judge Kathe M. Tuttman after his bombshell change of plea.
"'I don't think it's right when women use their kids against their fathers,' Jared Remy said, standing shackled and under armed guard just feet from Martel's shattered parents, Brian and Patricia Martel."
Doug Saffir of Boston.com reports Jared Remy is willing to take the blame for the situation he's in rather than having the public blame his own family.
Saffir wrote,"In a statement after his sentencing, Remy said 'blame me for this, not my family.' The Boston Globe reported that he also said,'And if you asked my family, they'd rather have me dead than her.'"
The Martels also issued a statement of their own, courtesy of their spokeswoman, Nancy Sterling, per Sweet.
"We do not have words to express our emotions regarding the tragic and senseless murder of our daughter, Jennifer. We hope that Jared has remorse for what he did to her and to our granddaughter.
"If just one family learns from our tragedy by recognizing the warning signs of domestic violence, it will help us to honor Jennifer's memory."
Sixty-one-year-old Jerry Remy has been enjoying a successful career as a Boston Red Sox color commentator since 1988.
In addition to his sportscasting career, Remy has several business ventures which include a hotdog stand known as "RemDawg's" and Jerry Remy's Sports Bar & Grill, which has three branches in the local Boston area.
He was inducted into the Boston Red Sox Hall of Fame in 2006.