She ended up in Florida, where she found Pamela Hutchinson, 59, a woman who looked like her.
A nationwide manhunt resulted in the apprehension and arrest of Riess at a South Padre Island, Texas restaurant. She was arrested about 25 minutes later.
Hutchinson "was a friend to everybody", her cousin, Daniele Watts Jeffreys, told HLN's Ashleigh Banfield.
Smith says when she had been detained Riess wasn't armed.
The Missoula County Sheriffs Office is offering a $10,000 reward for any helpful information in the investigation into the homicide of Susan Wood.
She was apparently headed to Florida.
By that time, Lois Riess was gone. "(Thursday night), she sits in a jail cell in Texas. "We are working as expeditiously as possible to bring her back to Lee County to face murder charges".
For almost four weeks, Riess, 56, of rural Blooming Prairie had evaded police who wanted her for the shooting deaths of two person - her husband David Riess, 54, who police say died of multiple gunshot wounds, and Pamela Hutchinson, 59, who police say that Lois Reiss had only just met and whom Riess had targeted due to their similarities in looks and body shapes.
Police say a lady and also also a lady in Florida experienced turned right into a South Texas vacationer town motel and had been interacting in a bar if she had been detained.
Riess was reportedly drinking and having a good time. Authorities released video showing Riess approaching the store cashier, buying a sandwich and asking for directions south, out of the state.
The Lee County Sheriff's Office in Florida says Riess drove her Cadillac Escalade from Minnesota to Fort Myers Beach and abandoned it at a park.
Riess is also accused of using that same gun to kill Pamela Hutchinson, who she met at a brewery in Florida.
Authorities were called to an area of Fort Myers Beach on April 9 and found Hutchinson dead in her condominium, with gunshot wounds.
A grandmother accused of killing her husband before traveling across the country to impersonate and kill another woman, has been arrested in Texas, authorities said. Her identification was missing along with her auto.
Hutchinson resembled Riess, who police said stole the victim's identity and auto.
Below is the last photo of Riess before she was captured, according to Inside Edition. She used Hutchinson's credit card to pay for a room.
Her arrest comes four days after Hutchinson's auto was seen about 50 miles from Corpus Christi, Texas.
Riess was arrested Thursday in South Padre Island, Texas thanks to a tip given to U.S. Marshals.