Robert Bowers has been released from the hospital and is "no longer at Allegheny General," a hospital spokeswoman said Monday.
Stephanie Waite said Mr. Bowers was released at 9:45 a.m, but provided no information about where he is going from there.
Later Monday, Mr. Bowers is expected to appear in federal court on charges related to Saturday's shooting at the Tree of Life synagogue in Squirrel Hill that left 11 dead and six others injured.
Mr. Bowers, 46, of Baldwin Borough, is accused in the shooting deaths and charged with 29 federal counts, including obstruction of exercise of religious beliefs resulting in death and use of a firearm to commit murder during a crime of violence, among others.
He also faces charges at the state level, including 11 counts of homicide, six counts of attempted homicide, aggravated assault and ethnic intimidation.
Baldwin-Whitehall School District on Monday confirmed that Mr. Bowers attended the district's high school.
The district, in a statement from Superintendent Randal A. Lutz, indicated that Mr. Bowers, 46, attended the high school from August 1986 to November 1989. That timeline suggests that he did not graduate, but the district indicated that any other details are considered confidential.
Neighbors of Mr. Bowers have suggested that he spent some time working in the trucking business.
"It is my firm belief that our focus must remain, not on the gunman, but on honoring the lives of the victims and offering our unwavering support to the victims' families," wrote Dr. Lutz. "I know the entire Baldwin-Whitehall community feels a deep sense of shock and sadness and we grieve together with the victims' families, our neighbors in Squirrel Hill and our friends in the Jewish faith."
He added: "By learning to see our classmates, coworkers, and neighbors as ourselves, we each take one step closer to living in a stronger, safer, and more loving community. When we value one another despite our differences, the idea of harming another becomes unthinkable."
Federal prosecutors have begun seeking approval to pursue the death penalty for Mr. Bowers, according to the U.S. attorney's office in Pittsburgh. City officials have called Saturday's attack the "darkest day in Pittsburgh's history."
Mr. Bowers is expected to appear before U.S. Magistrate Judge Robert C. Mitchell at 1:30 p.m.
Mr. Bowers, who authorities said went into the Tree of Life synagogue armed with an AR-15-style assault rifle and three handguns, was shot by police during Saturday's incident. He underwent surgery.
According to the affidavit of probable cause, Mr. Bowers told authorities while he was receiving medical treatment that "he wanted all Jews to die and also that they (Jews) were committing genocide to his people."
Authorities say Mr. Bowers also used a social networking site — Gab.com — to express hatred for Jews and immigrants in the weeks prior to Saturday's shootings.