UPDATE - 2:38 p.m. - Massachusetts State Police have confirmed that murder suspect Christopher Piantedosi turned himself in at the Weston State Police barracks at 1 p.m. He will be handed over to Burlington police. The Middlesex County District Attorney's Office will hold a news conference at 3 p.m. to announce what has been described as a "significant development" in the case.

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Full text of earlier article continues below.

The man known as New Hampshire's “remorseful robber” is now wanted for murder after a woman was fatally stabbed in her Burlington, Mass., home Thursday night.

An arrest warrant was issued Friday morning for Christopher Piantedosi, 39, of Methuen, Mass., on one count of murder.

Piantedosi, who is believed to be the murder victim's husband or boyfriend, is the same man who admitted to stealing a Hampstead woman's wallet and GPS from her purse while she was shopping at a Plaistow Market Basket on July, 18, 2011.

He later mailed the wallet back to her and then showed up at her house to return her $90, plus an extra $10, wrapped up in an apology letter along with her stolen GPS and a new charger. Piantedosi signed the letter “Stupid” and was later dubbed the “remorseful robber” by Plaistow police. He eventually turned himself in.

Massachusetts authorities are now asking for the public's help in finding Piantedosi once again. He is believed to be driving a brown, four-door Honda Civic with Massachusetts license plate 581MC8. He may be armed and dangerous, authorities said.

According to the Middlesex District Attorney's Office, Burlington police responded to 23 Forbes Ave. at 6:45 p.m. Thursday for a report of a stabbing. Upon arrival, officers found the female victim, identified as Kristen Pulisciano, 38, who lives at the home. She suffered stab wounds and was pronounced dead at the scene, authorities said.

The killing comes seven months after Piantedosi was given a suspended 30-day jail sentence on a class A misdemeanor theft charge in the 10th Circuit Court in Plaistow last September.

In an interview with the New Hampshire Union Leader after entering his plea, Piantedosi said he hoped to put his mistake behind him.

“I want to get this over with. This has ruined my life,” he said.

Piantedosi, who said he was a father of two teenagers, claimed that he wasn't a “professional purse snatcher” and that the Plaistow theft was his first.

“That's not what I do,” he said. “That was my first rodeo and I had a short career. Professional thieves don't return their loot.”

Piantedosi also told the paper writing the apology letter was “just me spilling my guts. I had to apologize. This isn't me.”

In his letter, Piantedosi hinted at some troubles in his life. He told the Union Leader =he had some financial problems while he was in between jobs after being laid off.

He also spoke about the aftermath of the theft case and the publicity surrounding it.

“This has affected my family. This has affected my job. They told me they'd call me when they need me. I went for an interview and they Googled my name and everything came up from every news station so they disqualified me,” he said.