A Texas sheriff announced Monday evening he's opened a criminal investigation into flights Florida Gov. Ron DeSantis (R) arranged last week that took some 50 Venezuelan migrants to Martha's Vineyard, Massachusetts.

Driving the news: DeSantis insists the flights were voluntary. But the Bexar County sheriff's office said in an emailed statement that it "has opened an investigation into the migrants that were lured from the Migrant Resource Center" in the county, where San Antonio is located.

• They were then flown to Florida, "where they were ultimately left to fend for themselves in Martha's Vineyard," according to the statement.
• The sheriff's office said it was "working with private attorneys who are representing the victims and advocacy groups while "preparing to work with any federal agencies that have concurrent jurisdiction, should the need arise."

Worth noting: Bexar County Sheriff Javier Salazar said at a news conference that it was unclear whether any laws were broken, but the migrants were "lured under false pretenses" into staying at a hotel before being flown to Florida and then Massachusetts.

• He said they "were promised the solution to several of their problems," including work.
• Lawyers for some of the Venezuelan migrants flown to Martha's Vineyard told Axios they were given misleading brochures promising "up to 8 months of cash assistance," employment services, and housing assistance, "at some point during their expulsion and relocation from Texas and Florida."

The big picture: DeSantis last week joined Texas Gov. Greg Abbott (R) in transporting migrants and asylum seekers by bus and plane to predominantly Democratic-run cities as they challenge President Biden's immigration policies.

What they're saying: DeSantis told Fox News' "Hannity" on Monday night that the migrants had volunteered to go on the flights and "all signed consent forms to go." They were provided with "a packet that had a map of Martha's Vineyard" and contact numbers for immigration and refugee agencies, he said.

• Representatives for DeSantis said in a statement earlier: "Immigrants have been more than willing to leave Bexar County after being abandoned, homeless and 'left to fend for themselves.'"
• The statement added that "Florida gave them an opportunity to seek greener pastures in a sanctuary jurisdiction that offered greater resources for them, as we expected."

Go deeper... DeSantis: Florida will keep relocating migrants with state funds

Editor's note: This article has been updated with new details throughout.