Jay Cantrell, a 51-year old inmate who was spending time at Muri Stein Hospital escaped through a window after security guards were caught sleeping on the job.
Nevada Corrections Department spokesperson Brooke Keast says he had been in the hospital since March undergoing evaluations for an upcoming trial.
Cantrell was previously being held at High State Desert State Prison.
He is 6 feet tall, with brown hair and brown eyes. He weighs 185 pounds. Officials say he was last seen wearing a navy blue pants, a black and white Adidas shirt and black shoes. Cantrell has a tattoo of a clown on his left shoulder.
He had previously filed complaints against the Nevada Corrections Department, claiming they had violated his civil rights. That suit was dismissed in 2011.