Members of a Texas search and rescue team were headed to Aruba Tuesday to aid in the search for missing U.S. teen Natalee Holloway (search).
Meanwhile, the family of the Alabama high school honors student said they were preparing a lawsuit that demands Aruban authorities share what evidence they have.
Aruban authorities have come under fire as media reports have portrayed the Caribbean island's efforts in the investigation as less than satisfactory.
A spokeswoman for the island's prosecutor's office defended the pace of the probe on Tuesday. "We are still keeping all our options open. ... We are working as fast as our system allows us to work and still be meticulous," Mariaine Croes told FOX News.
A judge on Monday ruled that the fourth suspect arrested in the case, Steve Gregory Croes, be held until at least next Tuesday. The 26-year-old party boat disc jockey was arrested last week in connection with Holloway's disappearance May 30.
Mariaine Croes, no relation to the suspect, confirmed on Tuesday that a third suspect, Deepak Kalpoe, 21, was moved to prison Monday night. Already in jail are his brother, Satish Kalpoe, 18, and a 17-year-old Dutch teen, Joran van der Sloot.
Van der Sloot and the two Surinamese brothers were among the last people reported to be with Holloway the night she disappeared. The Kalpoe brothers told police they took Holloway to a northern beach but dropped her off at her hotel, where they claim she was approached by a security guard.
Croes said he knew one of two Surinamese brothers being held in the case because they went to the same Internet cafe, according to Marcus Wiggins, Croes' employer on the party boat Tattoo. It was not known what other connection he may have had to either the brothers or to van der Sloot, the son of a justice official in Aruba. The boat Tattoo docks near the Holiday Inn where Holloway was staying.
Meanwhile, a source close to the investigation told FOX News that evidence taken from two cars impounded from the van der Sloot residence will be taken to The Netherlands for testing.
The source also said the FBI only helped with the exterior search of the Dutch teen's home but did not go inside the structure.
The FBI is now swapping out agents who have been there since early June. Two agents from Birmingham, Ala., will now be joining the team, which specializes in evidence collection and processing.
Early in the investigation a sample from the backseat of the teen's car was sent to an FBI lab in Virginia. The source said the Aruban authorities are increasingly relying on Dutch forensics teams instead of the FBI.
The family of the missing girl has been frustrated by the lack of unity and the slow pace of the search. Holloway's uncle, Paul Reynolds, told Court TV Monday that the family has contracted the Dickinson-based Texas EquuSearch Mounted Search and Recovery Team (search) to carry out a search of the island.
"They are going to help us search for Natalee in ways we couldn't before," Reynolds said without offering details.
Texas EquuSearch, made up of volunteers, said on its Web site that a team is traveling to Aruba this week.
The missing honor student's mother, Beth Holloway Twitty, told The Associated Press on Monday that the family has contracted an Aruban lawyer and was preparing a lawsuit demanding access to all information and potential evidence that police and prosecutors have gathered.
"I want to see the police record from May 30th," said Holloway Twitty, who has insisted the three young men hold the key to the investigation and that authorities should press them harder to tell the truth.
Croes, the attorney general's spokeswoman, said a judge would not rule on such a suit until any suspects were indicted.
In an interview with FOX News' Greta Van Susteren, Natalee's mother said she is confident van der Sloot and the Kalpoe brothers know what happened to her daughter.
"I have absolutely no doubt at all" that these three men know what happened to Natalee, Holloway Twitty said.
"When van der Sloot approached the vehicle I was seated in he had the most condescending, arrogant ... attitude of any 17-year-old I've ever seen," Holloway Twitty said when recounting an early encounter she had with the Dutch teen after arriving on Aruba.
Holloway Twitty said she was holding a photo of her daughter and said, "I told him 'I want my daughter' and he said, 'What do you want me to do.'"
Holloway, of Mountain Brook, Ala., disappeared in the early hours of May 30, the last day of a five-day school trip with 124 students celebrating their high school graduation. Her passport and packed bags were found in her room.
Investigators refuse to say whether they believe Holloway is dead. Holloway Twitty has said she will continue to believe her daughter is alive until she has proof to the contrary.
The Associated Press contributed to this report.