SAN FRANCISCO — New York State’s top prosecutor is investigating why American cellphone carriers have yet to embrace antitheft software on Samsung smartphones, raising questions about possible coordination among the biggest carriers.

On Tuesday, the New York State attorney general, Eric T. Schneiderman, sent letters seeking information to the chief executives of five carriers, Randall L. Stephenson of AT&T, Daniel S. Mead of Verizon Wireless, Daniel R. Hesse of Sprint, John Legere of T-Mobile US and Kenneth R. Meyers of U.S. Cellular.

In the letters, Mr. Schneiderman requested detailed information on why the carriers were not supporting a so-called kill switch that Samsung Electronics wanted to load on its phones. The feature would have allowed users to “brick” their phones, or disable the devices remotely, to discourage criminals from stealing them.

“If carriers are colluding to prevent theft-deterrent features from being preinstalled on devices as means to sell more insurance products, they are doing so at the expense of public safety and putting their customers in danger,” Mr. Schneiderman said in a statement.