Four days after two teens ran away from their Lakeville home, their mother and a friend took the girls to a western Minnesota horse ranch and left them there, until they were found two and a half years later, according to amended criminal charges released Monday.

The discovery of Gianna and Samantha Rucki last week led to three additional charges for Sandra Grazzini-Rucki, 50, who was arrested on Oct. 18 and now faces six felony counts of deprivation of parental rights. A search warrant of a St. Cloud home raided last month shows Lakeville police and U.S. marshals worked for months to build a case against Grazzini-Rucki and then track her down to a Florida resort and spa.

Should Grazzini-Rucki be convicted, the county is seeking an aggravated sentence against her, saying she caused the girls' father "particular cruelty" for depriving him of the girls for two years.

David Rucki has "suffered extreme emotional pain beyond what is normal for this crime," Assistant Dakota County Attorney Kathryn Keena wrote in a notice to the court filed last week.

Rucki declined to comment Monday. The Rucki family said in a statement on Friday that they were "ecstatic to have the girls home safe."

"Thank you for the kind thoughts and prayers, and we hope to continue to receive support from the community moving forward on this healing journey," the statement said.

Grazzini-Rucki, who is being held in lieu of $1 million bail, did an interview with ABC-TV's "20/20," her attorney, Michelle MacDonald, said Monday.

Grazzini-Rucki has declined to speak with the Star Tribune since she was arrested, though in an April interview she denied any involvement with hiding the girls.

The other woman referenced in the criminal account was not named. Lakeville police Lt. Jason Polinski said that several more people will be charged in connection with the girls' disappearance and that details about the girls' time at the horse ranch will be provided.

Gianna and Samantha, now 16 and 17, are doing well, Polinski said, but declined to elaborate further to protect their privacy.

The girls ran away from their home on April 19, 2013, amid a bitter custody battle between their parents. Before they disappeared, the teens repeatedly accused their father of abuse, but a court-appointed psychologist concluded that Grazzini-Rucki had brainwashed them. In November 2013, Dakota County Judge David Knutson granted Rucki full custody of his children, saying there was no credible evidence that he abused the girls.

Warrants served

Lakeville police have been investigating the case almost since the day the girls disappeared, court records show.

Soon after they went missing, an officer visited an Elko home owned by Grazzini-Rucki's boyfriend but never saw the girls.

In the summer, a detective checked out leads in North Dakota and Wisconsin sent by the National Center for Missing and Exploited Children, but those turned out to be cases of mistaken identity.

Lakeville police obtained search warrants of the girls' Facebook pages but found no new information. In November 2014 police served a warrant on Grazzini-Rucki's employer, US Airways, where she worked as a flight attendant, asking for her address, phone number and flight information. Two months later, the airline complied, but none of the information brought them any closer to finding Grazzini-Rucki or her daughters.

Polinski said photos recovered during later searches showed Grazzini-Rucki with a friend in different places around the world.

It wasn't until April 2015 that police got a new lead, when the Star Tribune reported the statements of a self-described witness to the girls' flight. Dale Nathan, a longtime critic of family courts and a suspended attorney, said that when Samantha and Gianna ran away, their mother picked them up in her car, and that he drove around with the three of them for two to three hours before he was dropped off.

Soon after, Star Tribune blogger Michael Brodkorb started reporting on the case and interviewed Nathan. Brodkorb wrote in a blog post that Nathan had information on his computers about the girls, but would not turn that over the law enforcement.

Homes searched

Police searched Nathan's home in August, where they say they recovered computers that had about 29,000 e-mails. Among those was a message sent two days after the girls went missing from Dede Evavold, a friend of Grazzini-Rucki's, according to the search warrant. Attached to those e-mails were two typed letters from the girls, with handwritten notes under the signatures.

Police raided Evavold's home on Oct. 21, taking numerous computers, flash drives and phones. Lakeville police say they found evidence from Evavold connecting the girls to the White Horse Ranch in Herman, Minn.

Police went there hoping to find more information about the girls' whereabouts, but instead found the sisters.

The owners of the horse ranch, Gina and Dale Dahlen, have declined to comment on the case.

The ranch, situated among cornfields and prairie, is about 160 miles west of the Twin Cities. On its website the White Horse Ranch describes itself as a nonprofit where abused children can heal by working with horses: "Broken children and hurting horses are able to bring each other to a place of healing through God's unconditional love."