State authorities began a second day of court-ordered DNA testing Tuesday on members of a polygamist sect, an effort they hope will begin to untangle the group's complicated family relationships.

Officials in a massive custody case are trying to identify the parents of 437 children taken from a West Texas compound more than two weeks ago. The testing of ranch residents was taking place in the courthouse square as a handful of deputies in cowboy hats stood guard.

David Williams, 32, a former member of the Fundamentalist Church of Jesus Christ of Latter Day Saints, came on his own from his home in Nevada, hoping to take custody of his sons. Williams said he doesn't pay attention to the news and only heard his three sons were in state custody from a friend.

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Clutching a Book of Mormon and photos of the boys ages 5, 7 and 9, Williams looked at his feet as he said his children were "taken hostage by the state."

"I have been an honorable American and father and I have carefully sheltered my children from the sins of this generation," Williams said. He declined to describe the mother of the boys as his wife, and declined to offer details of why or when he left the sect.

A judge ordered last week that the DNA be taken to help determine the parentage of the children, many of whom were unable to describe their lineage. Some of the adults have been ordered by the state to submit to testing; others are being asked to do so voluntarily.

Authorities believe the sect forces underage girls into marriages with older men. No one has been arrested, but a warrant has been issued for member Dale Barlow, a convicted sex offender who has said he has not been to the Texas site in years.

Rod Parker, an attorney for the FLDS, said he is afraid authorities secretly intend to use the DNA to build criminal cases against members of the group. But state Child Protective services spokesman Greg Cunningham said: "We're not involved in the criminal investigation. That's not our objective."

Ten lab technicians hired by the state spent Monday collecting samples at the San Angelo coliseum and fairgrounds serving as a shelter for the children who were removed from their Eldorado compound during an April 3 raid.

Some of those technicians were to be sent to Eldorado on Tuesday to collect samples from the possible parents. Family relationships are immensely tangled within the sect, where multiple mothers live in the same household and children refer to all men in the community as "uncles."

Authorities say they need to figure that out before they begin custody hearings to determine which children may have been abused and need to be permanently removed from the sect compound, and which ones can be safely returned to the fold. For now, they're all in state custody because child welfare officials believe sexual abuse has occurred or could occur imminently because of the teachings of the sect.

State social workers have complained that sect members have offered different names and ages and had difficulty identifying their mothers.

Parker acknowledged that family names within the sect can be confusing, but said: "No one is trying to deceive anyone. ... It's not sinister." Instead, he said that because many of the sect's marriages are not legal, adults and their children may legally have one name but use another within the community.

The collecting of DNA is likely to take most of the week, and it will be a month or more before the results are available, said Janiece Rolfe, a spokeswoman for the Texas attorney general's office.

The children will be placed in group homes or other quarters until individual custody hearings can be completed by early June. Officials said they will try to keep siblings together when possible, though some polygamous families may have dozens of siblings.

The testing will involve 437 children and possibly hundreds of adults. State authorities revised their count of the children from 416 as they developed better lists and discovered that not all the female members who claimed to be adults were over 18.

Each person who submits to a test will be photographed, and the inside of his or her cheek will be swabbed to remove cells for analysis.

The DNA sampling is an enormous undertaking for a state that typically tests only 1,000 children a year.

Attorneys for the children and the adults have complained that they haven't had enough access to their clients at the coliseum. Texas District Judge Barbara Walther ordered Monday that the women and children there be allowed to use newly installed phone lines to contact their attorneys.