Leading senators on Thursday evening demanded in a letter that the Obama administration release the immigration records of the two suspected shooters who killed at least 14 people in San Bernardino, California, this week.

Sens. Ted Cruz (R., Texas) and Jeff Sessions (R., Ala.) claimed the Obama administration has failed to comply with a request for immigration records of 72 recent terrorists found to be in the United States.

The attacks this week, they said, highlight the need for greater oversight on those entering the country.

Devout Muslim Syed Rizwan Farook and his wife, Tashfeen Malik, who was born in Pakistan, are suspected of killing at least 14 people in an attack that some believe was motivated by the duo's potential ties to terrorists.

Cruz and Sessions are demanding to see their immigration records in order to shine more light on the case.

"We demand that you immediately provide the same detailed information requested in that letter for Farook and Malik, which would include the immigration history of their parents and any immigration documents related to their marriage and her subsequent travel to the U.S," the senators wrote.

It is critical that the Obama administration is more transparent about information pertaining to recent immigrants, according to the senators.

"We are dealing with an enemy that has shown it is not only capable of bypassing U.S. screening, but of recruiting and radicalizing Muslim migrants after their entry to the United States," the two wrote to the secretaries of state and homeland security as well as the attorney general.

"The recruitment of terrorists in the U.S. is not limited to adult migrants, but to their young children and to their U.S.-born children—which is why family immigration history is necessary to understand the nature of the threat," they wrote.

"Farook is the child of immigrants who came to the United States from Pakistan, and Malik [his wife, a native of Pakistan] travelled to the U.S. from Saudi Arabia," according to the letter.

Congress needs this information ahead of its consideration of a yearly spending bill that will pave the way for some 170,000 migrants from Muslim-majority nations to enter the United States.

"The security task involved is immense, and Congress must have the requested information [about terrorist immigration histories if lawmakers are to act as responsible stewards of American immigration policy," the letter said.

At least 12 individual tied to terrorists have entered the United States in the first eleven months of 2015, the senators said.

"In the first 11 months of this year, we have already identified 12 individuals brought into the country as refugees who have been subsequently implicated in terrorism. Their countries of origin range from Bosnia, to Somalia, to Uzbekistan," they wrote. "These events do not occur in isolation, but tend to be part of broader networks of radicalization and extremism that must be understood as we develop immigration policy."