Arizona prosecutors eight months ago dropped charges against a polygamist who had allegedly married underage girls on the Utah line, said a woman who has been working for 14 years to bring the polygamist back from Mexico.

Following the slaying of three of his family members in Mexico, Orson William Black, 56, finally returned to the United States on Thursday and is being held at a detention center in El Paso, Texas. But the woman who has been pursuing him, Pennie Petersen, on Saturday said he’ll be free this time next week if the Arizona attorney general doesn’t reinstate the child sex-abuse charges.

“When he gets out of that jail cell in El Paso, if he thinks the heat is on him, he’s gone,” Petersen said in a phone interview.

Petersen has started an online petition asking Arizona Attorney General Mark Brnovich to refile the charges.

(Ross D. Franklin | AP Photo) Arizona Republican candidate for Attorney General Mark Brnovich talks to supporters at the Republican election night party Tuesday, Nov. 4, 2014, in Phoenix.

A spokeswoman for Brnovich did not return a message seeking comment on Saturday. A search of Arizona court records on Saturday showed no active prosecutions or warrants for Black.

Meanwhile, Petersen and news outlets in Mexico on Saturday reported that it was members of a drug cartel who killed three of Black’s family and followers in September. Mexican and U.S. authorities raided Black’s hideout Nov. 5 in part to protect him and his followers from further violence.

Black was a member of the polygamous The Fundamentalist Church of Jesus Christ of Latter-Day Saints but split from that group in the 1980s. The FLDS began after the mainstream Mormon church disavowed polygamy in 1890.

Black was charged in 2003 in Mohave County, Ariz., with two felony counts of conspiracy to commit sexual conduct with a minor and three felony counts of sexual conduct with a minor. Black fled before he could be prosecuted.

The Arizona attorney general’s office filed the charges and alleged Black had married two girls underage. One of the counts, according to a 2003 article by the Phoenix New Times, refers to a child conceived by an underage bride — a boy born in December 1998 and named Robert William Black, who was one of three teens or young men killed in September.

Petersen on Saturday described a story that’s bizarre even by polygamous sect standards.

She said she and her family are from the FLDS community of Hildale, Utah, and Colorado City, Ariz. Black, who goes by his middle name, married three of her sisters and two of her nieces, Petersen said. Petersen helped prosecutors from Arizona build the case against Black.

When Black fled, Petersen said, she began working with the U.S. Marshals Service to find him. Eight months ago, a deputy marshal called her and said Black had been located in Ciudad Cuauhtémoc, Chihuahua. Black was living on a 5-hectare property called Rancho Negro, Mexican news outlets reported Saturday.

Petersen was ecstatic. There was a U.S. Marshal team on the ground in Ciudad Cuauhtémoc to make the arrest. Then the deputy marshal called her back, saying Brnovich’s office was thinking of dropping the charges.

“We were minutes, I mean we were minutes, from grabbing William,” Petersen said Saturday.

Over the next two weeks, Petersen said, she and federal authorities and staff from Brnovich’s office went back and forth on whether to proceed. The Arizona prosecutors said evidence had been lost and the case was weak. Petersen suspects the prosecutors were really just probing her to see how much of a public fight she’d put up if Black’s charges were dismissed.

“They called me back and said, ’Our uppers said we are dropping the charges. It’s done,” Petersen recalled.

Then on Sept. 9 or 10, Petersen says an FBI agent called her.

“They said, ‘Pennie, we’ve got three dead boys here. They’re your relatives.’”

Someone examines a travel trailer In this photo provided by the law enforcement in the Mexican state of Chihuahua, Orson William Black, 56, was arrested in Chihuahua Nov. 5, 2017. Black is a former member of the polygamous Fundamentalist Church of Jesus Christ of Latter-Day Saints who has been on the run from child sex abuse charges in Arizona since 2003. Courtesy Photo.

Mexican authorities have identified the dead only as being ages 15, 19 and 23, with the names Robert W.B., Jesse L.B. and Michael B. One of the dead, Jesse Barlow, is Black’s stepson, Peterson said. The other two victims are Black’s sons, she said.

Petersen has been told by U.S. authorities that Black was manufacturing methamphetamine for a drug cartel. Black had some falling out with his employers, Petersen said, and assassins came looking for him.

Black wasn’t at home and the gunman watched his ranch for three days, Petersen said. Then the gunman lost patience.

One or two days before the FBI called Petersen, the cartel members killed one of the victims at the property gate. Then they went to the house and killed the other two as they held hands in front of the home, she said.

The assassins told the remaining people at the ranch that Black needed to surrender or they would return, kill everyone older than 6 and take those ages 6 and younger, Petersen said Saturday.

A Zebra head was among the exotic stuffed animals found with polygamist Orson William Black, according to this photo provided by Mexican law enforcement. Police in the Mexican state of Chihuahua arrested Black Nov. 5, 2017. Black is a former member of the polygamous Fundamentalist Church of Jesus Christ of Latter-Day Saints who has been on the run from child sex abuse charges in Arizona since 2003. Courtesy Photo.

After the Nov. 5 raid, Black was transported to El Paso. It’s unclear if he was extradited or, as Petersen said Saturday, whether he was deported. She said Black is still in custody because the arrest warrant from Mohave County had not been deleted from a federal law enforcement database and it could take up to 10 days for the discrepancy to be resolved.

Meanwhile, Petersen said, 26 of Black’s family and followers have been deported. They were on their way to polygamous communities on the Utah-Arizona line Saturday.

“We had to save them and to save them we had to get them deported,” Petersen said.