BOSTON (AP) — U.S. Sen. Elizabeth Warren is calling for an expedited criminal investigation into the death of a patient at the Bedford, Massachusetts VA Medical Center.

William R. Nutter Jr., a Vietnam War veteran who served 21 years in the U.S. Army Reserves, died July 3, 2016.

Warren cited reports in The Boston Globe and The Lowell Sun, saying Nutter's death was due in part to neglect.

The Massachusetts Democrat said patients at the medical center are heroes who deserve the highest quality care.

Warren said she's raised concerns about the reported problems at the medical center in recent months, including allegations that employees engaged in inappropriate relationships with patients and sold narcotics on hospital grounds.

On Friday, Warren wrote to Veterans Affairs Secretary David Shulkin asking he expedite the investigation into Nutter's death.