The man being sought for allegedly killing his estranged wife Saturday in her east Cobb County home was arrested earlier this year and charged with stalking the woman.

John Stephen Kristofak, 58, is being sought in the death of Donna Nations Kristofak, 48.

Donna Kristofak was found unresponsive late Saturday morning by police responding to a 911 call at her home on Tall Pine Drive near Walton High School.

She was taken to Wellstar Kennestone Hospital, where she later died of her injuries, according to Cobb police spokesman Michael Bowman.

John Kristofak remained at large Monday morning. Police say he is armed and dangerous. He faces charges of aggravated assault and murder, and was last seen driving a brown Chevrolet Equinox with Georgia tag BUV 2635.

According to a March 28 warrant for his arrest, John Kristofak, in violation of a temporary restraining order, “did contact the victim for the purpose of harassing, threatening and intimidating her.”

Between March 9 and March 19, Kristofak “called the victim’s place of work 12 times and used vile, vulgar language to her and her coworkers,” the warrant stated.

The warrant also accused Kristofak of sending an e-mail to Donna Kristofak on March 19, that read, “you are in danger – protect yourself. No one can help you at this point. You won’t know where it is coming from.”

Another e-mail sent four minutes later read, “I warned you never cut me off from my children. You did and you will pay,” according to the warrant.

Minutes later, another e-mail allegedly asked his wife, “have you ever been hit by a car going 140 not knowing where it’s coming from?”

Later that evening, John Kristofak allegedly advised his wife in an e-mail to “make your final goodbyes with your children.”

John Kristofak was arrested on the first warrant on March 29, and a day later, a second warrant for aggravated stalking was issued, alleging that he followed his wife in the parking lot of a Wal-Mart, and “at one point pulled his vehicle in front of Donna’s in an attempt to stop her from leaving.”

Police ask that if anyone sees John Kristofak, they should call 9-1-1 immediately. Anyone with information that could assist investigators with this case is asked to call (770) 499-3945.