Born in Vega Baja, Puerto Rico, Sánchez received a Bachelor of Arts degree from City College of New York in 1978 and a Juris Doctor from the University of Pennsylvania Law School in 1981.

He was a Staff attorney of Legal Aid of Chester County, Pennsylvania, from 1981 to 1983.

On August 1, 2018, Sánchez became the first Latino chief judge of the Eastern District of Pennsylvania, due to the announced retirement of Lawrence F.

In February 2019, Sanchez found that the University of the Sciences had not breached its contractual promise of a fair process when it expelled a student accused of campus sexual assault without providing a live hearing or an opportunity to cross examine witnesses.

[3][4] His judgment was then reversed by the unanimous United States Court of Appeals for the Third Circuit in May 2020.