The New York Attorney General and San Francisco District Attorney applaud the move, but say it falls short of their goal of having antitheft measures enabled by default on all devices.
On the heels of proposed California legislation, federal lawmakers also get on board with a bill requiring security features on all cell phones.
The attorney general pens letters to the major US wireless carriers and says "it's disturbing that the nation's leading smartphone carriers knowingly dismissed technology that could save lives."
The results of attempts to crack the antitheft security on Apple's iOS 7 and Samsung's Galaxy S4 Lojack system are still being compiled.
Apple and Samsung's latest phones and their antitheft technology are being tested by state and federal governments on Thursday.
A bill requiring smartphone makers to include antitheft software on devices sold in California is one step away from becoming law.
Law requires security software to come enabled by default, but other than that, not much will change for most smartphone users.
If kill switches became standard in all phones, consumers could save big on replacement phones and insurance coverage, according to a researcher from Creighton University.
Robberies in NY involving Samsung devices increase by 40 percent during the start of 2014, according to a new report.
The phone maker has added heftier antitheft software to its flagship phone, as more lawmakers call for technology that protects smartphone owners from being robbed of their devices.