New York Attorney General Eric Schneiderman told CNBC that BofA and Wells Fargo were the leading violators of a settlement designed to end mortgage servicing abuses, and that's why he plans to sue on behalf of homeowners in his state.
"The mortgage servicing settlement agreement has 304 different standards and deadlines that banks have to [legally] comply with," he said in a " Squawk Box " interview Tuesday. "These two banks were far out in front of every other institution in terms of violations."
(Read More: New York to Sue BofA, Wells Fargo Over Mortgages )
In February 2012, BofA and Wells Fargo were among five banks that agreed to the $25 billion settlement over faulty foreclosure practices and the mishandling of requests for loan modifications.
"What happened over the past decade, it is unprecedented and it has convinced the American people that the Street is a rigged casino. That offends me," Schneiderman continued, "and we're looking to correct that impression by entering into an agreement ... you have to comply with the rules."
Schneiderman did not say how the other three banks-JPMorgan Chase, Citigroup and Ally Financial-were performing, but told CNBC that there are "other investigations" in progress.
The New York attorney general's announcement comes ahead of a key report from the monitor of the settlement-its first assessment of compliance on troubled borrowers, including how quickly banks must respond to requests for loan modifications.