Inspired by his own experience living in a New York City apartment building that was converted into high-priced condos, a 71-year-old lawyer and former state regulator is taking on developers citywide on behalf of seniors and disabled tenants.

Walter Goldsmith, a founding partner at Goldsmith & Fass, claims in Joseph Quenua v. Carnegie Park Associates, filed late Tuesday, that landlords have ignored a decades-old law that requires them to give tenants 62 and older and those with disabilities the option to stay on as renters in their apartments rather than move away or buy the apartment themselves.