Weeks after her last known contact with loved ones who shared grave concern for her safety, 33-year-old Ms Alcaraz was found safe in the Golden State with Mr Stratton, who was arrested on an unrelated outstanding warrant.
But questions remain around the circumstances of her disappearance, which bore chilling echoes of the bombshell Gabby Petito case.
Ms Alcaraz left her home in Tennessee with Mr Stratton to visit family in Orange County, California, earlier this month.
When authorities and her family first put out appeals for information on her whereabouts, Ms Alcaraz was thought to have been last seen in the New Mexico town of Moriarty on 6 May.
Two days earlier, sheriff’s deputies in Torrance County pulled the couple over after receiving reports that Mr Stratton had assaulted Ms Alcaraz.
The officers let them go without pressing criminal charges after Mr Stratton claimed he had also been hit.
This week, officials indicated that Ms Alcaraz had been spotted again at a California Walmart on 27 May.
Then, on the morning of 30 May, the couple were located together in the California town of Eureka.
Here’s what we know about the case:
Ms Alcaraz, a mother of two also known as Nikki Cunningham, departed from Cheatham County, Tennessee, in her 2013 Jeep Wrangler with Tennessee plates in late April bound for Orange County, to visit family.
Ms Alcaraz was travelling with her boyfriend Mr Stratton and a pet dog.
On 4 May, sheriff’s deputies in Torrance County, New Mexico, pulled the couple over after receiving a report that he had struck Ms Alcaraz.
Mr Stratton told authorities that he had also been hit, and both declined to press charges.
Authorities later released photos showing Ms Alcaraz with a black eye, cuts on her face and severe bruising on her arms after the alleged assault.
“He beat her up pretty badly,” her brother Josh Alcaraz told Fox5.
“A truck driver had to pull him off of her, call the police, the police picked him up, took him a couple exits down and dropped him off. She was diagnosed with a traumatic brain injury, and a broken hand or wrist.”
Ms Alcaraz was taken to a Super 8 motel in the town of Moriarty.
A friend travelled from California and stayed with her overnight at the motel. The plan was for the friend to take her back to California.
On 6 May, Ms Alcaraz left the motel and told the friend she was going to try to find her boyfriend. Her family said this was the last time she has been seen alive.
Her sister Toni Alcaraz told WKRN that she received a text on 8 May saying she was in Arizona, and planned to continue the trip to California. She didn’t hear anything after that.
Toni Alcaraz told the news site it was highly unusual not to hear from her for an extended period.
Ms Alcaraz’s licence plate was picked up near Flagstaff, Arizona, on 9 May. Her phone has reportedly been switched off.
This week, a Cheatham County deputy told News 2 that Ms Alcaraz was seen at a Walmart in Redding, California, on 27 May.
A photo released by the county District Attorney General Ray crouch shows her selling her phone at an ecoATM.
On Tuesday (30 May), Ms Alcaraz and Mr Stratton were located in Eureka at 7.15am, the Redding Police Department said in a news release.
“The Redding Police Department has been in contact with the Moriarty, New Mexico Police Department and confirmed Nikki is no longer considered a missing person,” the release stated.
On the same day, authorities released body camera footage from the 4 May incident, which showed both Ms Alcaraz and Mr Stratton with facial injuries.
Missing person investigation
Toni Alcaraz said she filed a missing persons report in New Mexico as that was where she was last seen.
Josh Alcaraz said he feared that his sister’s vehicle might have broken down in the desert or come off the road.
"We would like everybody to keep their eyes open, and if you see the Jeep, if you see him, if you see her, call somebody. Call the police," he toldFox5.
Officials in Cheatham County, Tennessee, were working with law enforcement agencies in New Mexico and California to try to locate Ms Alcaraz.
“Due to a history of domestic assault we believe she is in danger,” the Cheatham County Sheriff’s Office said in a Facebook post appealing for information.
Mr Crouch, the county DA General, told WKRN his office had requested a nationwide extradition for Mr Stratton, who was also missing.
Mr Stratton was wanted on an unrelated arrest warrant for theft and begged for the public’s assistance.
Family clung to the hope of finding Ms Alcaraz alive.
“If you see the Jeep, if you see him, if you see her, call somebody,” Josh Alcaraz told Fox5.
“Obviously, worst-case scenario is very present in the back of my mind. I’m trying to hold out hope.”
Ms Alcaraz was described as 5’6” with brown eyes and black/brown hair. She also has several distinctive tattoos.
Mr Stratton’s family reportedly did not file a missing person report, according to online reports.
Gabby Petito comparisons
The allegations of assault on a cross-country road trip have been drawing comparisons to the 2021 disappearance and murder of vlogger Gabby Petito.
Petito set off from her home in New York in July that year with her boyfriend Brian Laundrie.
The couple was pulled over in Utah by officers from the Moab Police Department on 12 August after receiving reports that Laundrie had struck Petito.
They were allowed to continue separately after Laundrie claimed he had been hit by Petito.
After a nationwide search and international media attention, Petito’s remains were found in the Grand Teton National Park in Wyoming in September.
Laundrie later shot himself in the head and left a suicide note confessing to killing Petito.
Petito’s family is suing the Moab Police Department for failing to follow the law and protect her during the traffic stop.
An independent review of the domestic assault incident found the officers had made several mistakes, and should have been classified as a domestic assault.
Petito’s family are also suing Laundrie’s parents Chris and Roberta for emotional distress.