A private plane carrying 20 migrants from Texas arrived in California's capital city of Sacramento Monday morning, officials said -- the second such arrival of migrants in the city from a conservative state in several days.

"Special Agents from the California Department of Justice are on the ground and have made contact with these individuals," said Tara Gallegos, a spokesperson for California Attorney General Rob Bonta.

Investigators have determined the migrants were asylum seekers and, like migrants who were flown in Friday, were carrying documents purportedly from the Florida government. The papers listed Vertol Systems Company Inc., as the contractor behind the flights.

Agents were aware the Monday flight was on its way and greeted the migrants.

The attorney general's office is working to confirm details about the migrants -- including their nationalities -- but said the plane that brought them to California was operated by the same contractor used in a charter flight that brought migrants to California on Friday, Gallegos added.

"We're investigating the circumstances by which they were brought to California," Bonta tweeted. "State-sanctioned kidnapping is immoral."

The 16 migrants who arrived Friday also had paperwork purporting to be from Florida.

Those migrants were taken from Texas to New Mexico, then flown in a private chartered jet to California, where they were "dumped on the doorstep of a local church without any advance warning," California Gov. Gavin Newsom said in a statement.

They were originally from Colombia and Venezuela, officials said.

Bonta said previously his office was investigating the first incident and "evaluating potential criminal or civil action against those who transported or arranged for the transport of these vulnerable immigrants."

Members of the first group told authorities while in Texas they were told to sign documents before they could board the plane to Sacramento, Gallegos said Monday. However, not all the migrants, who are not fluent in English, understood where they were headed and not all signed the forms, she said.

The migrants shared documents with investigators, including waivers saying they agreed "to participate in the state of Florida's voluntary transportation program," Gallegos said. The consent form indicates they understood "this program is administered by the Florida Division of Emergency Management."

CNN has reached out to state officials from Texas and Florida for comment.

The circumstances around who paid for the group's travel, and whether the migrants were misled with false promises, will be investigated, according to the governor.

On Monday, Newsom, a Democrat, called GOP Florida Gov. Ron DeSantis, who is also running for president, a "small, pathetic man" in a tweet, apparently referring to his alleged role in the first flight.

".@RonDeSantis you small, pathetic man. This isn't Martha's Vineyard. Kidnapping charges?" Newsom tweeted, linking to a California penal code that indicates a person from out of state who transports someone else to California "by force or fraud" could be found guilty of kidnapping.

Last year, DeSantis sent two planes carrying migrants to Martha's Vineyard, Massachusetts. Migrants have also been bused from border towns to sanctuary cities in recent years with little to no notice.

A Texas sheriff whose office has been investigating the transfer of migrants from that state to Martha's Vineyard in September said Monday he will file charges -- but didn't specify against who.

The office will recommend charges of unlawful restraint, both misdemeanor and felony, according to a statement from the office of Sheriff Javier Salazar, a Democrat.

The case is being reviewed by the Bexar County District Attorney's office. CNN has reached out to the office for comment.

In September, the sheriff said 48 migrants were flown to Martha's Vineyard for "a photo-op and stranded." He said he believes the migrants were "exploited and hoodwinked" into making the trip for political posturing.

DeSantis said at the time the migrants weren't misled.

"Why wouldn't they want to go, given where they were? They were in really, really bad shape and they got to be cleaned up, everything, treated well," he told Fox News in September.

The Florida Legislature has set aside $22 million for migrant transport.

California and Sacramento officials are not aware of plans for additional charter flights carrying migrants to California, but there is "probably a reasonable expectation" they will continue and the city is prepared, Sacramento Mayor Darrell Steinberg said in a news conference Monday.

"Sacramento is going to do everything it can to care for these vulnerable people who are dropped off at our doorsteps," Steinberg said. "No matter what the terrible motivation was from whoever did this, that's our job."

Steinberg said he has yet to meet any of the migrants but heard from people who spoke with them that they were scared but now "finally feel safe because they know that they are now in the arms of a community that cares about them."

White House press secretary Karine Jean-Pierre said the Biden administration is in close touch with state officials and said the incidents put "people's lives at risk."

"I've said it many times from here, repeatedly from this podium, that busing or flying migrants around the country without any coordination with the federal government -- we've talked about this -- state or local officials as well -- is dangerous and unacceptable. And we'll continue to be very, very clear about that.

"It is dangerous and unacceptable because you're putting people's lives at risk."

In October, the office of the Treasury Department's inspector general sent a letter to Massachusetts Sen. Ed Markey saying it would examine the Florida flights carrying migrants to Martha's Vineyard. The Oct. 7 letter said the department would audit the use of State and Local Fiscal Recovery funds, which were dispersed to help with recovery after the pandemic.