He was arrested last summer after a security camera photo of a flower-toting suspect at a Manhattan bank generated front-page headlines.
The bouquet, neatly bundled in pink tissue paper and plastic, concealed a note that demanded $50 and $100 bills.
He robbed a Manhattan branch of a Capital One Bank, as well as The Bank of Smithtown on Long Island. One of the robberies netted about $2,000, and the other about $400.
The 45-year-old Pemberton is set to be sentenced on Sept. 14.