Millie Weeks, 77, who CBC News confirmed formerly went by Melissa Friedrich, was arrested on Monday. She was found guilty of killing a previous husband and has also spent time in jail for stealing from a man she was living with in Florida.
Her current husband, a recent widower, became violently ill just days after the couple married.
Fred Weeks, 75, was taken on Sunday to the North Sydney General Hospital, where doctors became suspicious and called police.
After consulting the Crown prosecutor, police obtained a warrant for the woman’s arrest, and a search warrant for her home in New Glasgow.
Police transported her to Cape Breton Monday. She's being held in police custody and will appear in court on Tuesday.
In 1991, Weeks killed her husband Gordon Stewart of P.E.I. on a deserted road near Halifax. He had been heavily drugged when she ran him over twice with a car.
She was sentenced to six years in jail for manslaughter, and was released after serving two.
Stewart's sister Kate Reeves spoke to CBC-TV's fifth estate a few years ago about her brother's death.
"I am sure she will be pleading, 'I am a poor old lady,' by then. It doesn't matter. I'm sure it won't stop her criminal behaviour no matter how old she is and my brother didn't get a chance to get old," she said.
Weeks after being released from jail, Weeks travelled to Florida where she met Robert Friedrich at a Christian retreat. She sent him a letter, which said, "God wants us to be married."
They married in Dartmouth, N.S., in 2000, but a year later Robert's family noticed his health was faltering. He had mysterious fainting spells, slurred his speech, and was in and out of hospitals.
They said his money also began to disappear. He died in 2002 of cardiac arrest. No one was charged in his death.
Her next Florida love affair was with Alex Strategos, a 73-year-old divorced man she met on AmericanSinglesDating.com. On the day they moved in together he was taken to hospital after hitting his head.
He wound up being hospitalized eight times over a two-month period.
A strange drug was found in his system and his bank account was emptied.
Melissa Friedrich served five years in a Florida prison on three counts of grand theft from a person 65 years or older, two counts of forgery and two counts of using a forged document. Police said she coerced Strategos to give her power of attorney and then she siphoned off his money into her own bank account.
She was released from jail in 2009 and deported to Canada.
Her latest husband is said to be recovering, and the case is under investigation.
Police said members of the Major Crime Unit will continue to investigate and further details will be released as they become available.
Weeks is featured in the National Film Board documentary When Women Kill.