Mexico City • Prosecutors in northern Mexico say they have detained wanted U.S. polygamist Orson William Black Jr. and his followers and are investigating whether Black was involved in the death of three American youths whose bodies were found at a ranch in September.

The arrest of Black on Sunday — along with four of his wives, a woman described as “a concubine” and about 20 Americans without proper documents — marks the end of the fundamentalist sect leader’s long, strange period on the lam.

Few thought the trail to finding him would end in bloodshed.

The prosecutors’ office in the border state of Chihuahua says Black, 56, was captured in an area largely populated by Mennonites and is under investigation for the deaths of three Americans aged 15, 19 and 23 on Sept. 10.

In this photo provided with a redaction by the law enforcement in the Mexican state of Chihuahua, Orson William Black, 56, stands while being detained 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.

In keeping with Mexican legal practice, the office identified the victims by their first names — Robert W.B., Jesse L.B. and Michael B. — and suggested they may have all carried the last name Black.

Prosecutors did not say why Black was a suspect in the deaths, but suggested the victims may have been members of his religious group. Black was a member of 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 married two girls underage. One of the counts, according to a 2003 article by the Phoenix New Times, refers to one of the children conceived by an underage brides was a boy born in December 1998 and named Robert William Black. It was unclear Monday whether he is one of the murder victims.

As for the deaths found near Black’s Mexican hideout, prosecutors’ curiosity was piqued when members of the sect didn’t claim the youth’s bodies.

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.

“During the investigation, it was notable that the victims did not have birth certificates and that the members of the religious community who appeared to identify the dead did not claim the bodies, and so the U.S. consulate was contacted to provide information on this group,” the state prosecutors’ office said.

The U.S. Embassy in Mexico City was not immediately available to offer information on the case.

Authorities caught Black, who also goes by the first name Larry William, in a two-day series of raids on several different homes used as the sect’s “commune,” according to prosecutors.

The raids turned up a bizarre collection of 65 stuffed animals or animal heads, including zebras, buffaloes, a lion and a bear. Authorities also found frozen animal carcasses.

Black was charged with illegal possession of wildlife and human smuggling, and the Americans caught with him were turned over to immigration authorities pending possible deportation.

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.

Black has faced charges of sexual misconduct with minors in the U.S., but apparently fled to Mexico around 15 years ago.

He was able to hide successfully for years in an area in the northern state of Chihuahua where foreign religious sects go unnoticed.

The area is home to a Mennonite community which dates back to the 1920s and a community founded in the late 1940s by another sect from the United States that also broke away from the Mormon church after it disavowed the practice of polygamy.

Few of the families still practice plural marriage, and many are no longer practicing Mormons.

The townspeople now mainly farm, run cattle ranches and grow pecans.

Salt Lake Tribune reporter Nate Carlisle contributed to this report.