Faustin Nsabumukunzi, 65, was charged with covering up from US authorities his role as a local leader in Rwanda when the genocide began in 1994. An estimated 800,000 Tutsis were killed during the three-month-long genocide.
At an initial court appearance, Nsabumukunzi pleaded not guilty to visa fraud and attempted naturalization fraud and was released on $250,000 bail. The bail package requires home detention and GPS monitoring, but he will be allowed to continue working as a gardener.
Nsabumukunzi is alleged to have set up roadblocks during the genocide to detain and kill Tutsis and to have participated in killings, prosecutors said, citing witnesses.
"Nsabumukunzi used his leadership position to oversee the violence and killings of Tutsis in his local area and directed groups of armed Hutus to kill Tutsis," the federal prosecutors said.
He was subsequently convicted and sentenced to life in prison in absentia by a Rwandan genocide court, according to US legal papers.
The suspect was arrested at his home in Bridgehampton, New York, where he had settled as a gardener and beekeeper in an exclusive enclave on Long Island, according to the US media.
Prosecutors said he had lied to US officials in his immigration application, including by falsely denying any involvement as a perpetrator of the Rwandan genocide when he sought refugee status in 2003.
If convicted, Nsabumukunzi faces a maximum of 30 years in prison.
