Jared Loughner, the man accused in a 2011 shooting rampage that seriously wounded then-U.S. Rep. Gabrielle Giffords, will plead guilty Tuesday to murder and attempted murder, a source familiar with the deal told Fox News.
A court-appointed psychiatrist will testify Loughner is competent to enter a plea in the Tucson massacre that killed six people and injured 13, including Giffords. A possible plea deal would send him to prison for the rest of his life, a person familiar with the case told The Associated Press.
The plea and deal are contingent upon the judge agreeing Loughner is competent and allowing him to accept the plea, which are not certain in this case, the source says.
A status conference in the federal case had already been scheduled for Tuesday in Tucson.
Bill Solomon, a spokesman for the U.S. attorney's office, said Saturday he could not comment on Loughner's case and the possibility of a guilty plea.
The Pima County attorney's office, which has said it could also pursue state prosecution of Loughner, declined to comment, said spokeswoman Isabel Burruel Smutzer.
Loughner has pleaded not guilty to 49 federal charges stemming from the Jan. 8, 2011, shooting outside a Tucson supermarket where Giffords was holding a meet-and-greet with constituents.
Authorities said he shot Giffords, opened fire on the crowd and was subdued by bystanders. Giffords was shot in the head and subsequently left Congress to devote her time to rehabilitation.
Giffords and her husband were traveling in Europe, and spokeswoman Hayley Zachary said Saturday she had no information on developments in Loughner's case.
U.S. Rep. Ron Barber, a Democrat who was elected in June to replace Giffords in Congress after she resigned, also was wounded in the shooting. A spokesman for Barber did not immediately respond to requests for comment.
U.S. District Judge Larry Burns ruled previously that Loughner isn't psychologically fit to stand trial, but that he could eventually be made ready for trial after treatment.
An Arizona college that Loughner attended released numerous emails about him that painted a picture of a struggling student with emotional problems who disturbed others with his strange behavior.
Experts have concluded that Loughner suffers from schizophrenia, and prison officials in Missouri, where Loughner has been held, have forcibly medicated him with psychotropic drugs.
Even though psychologists have said Loughner's condition is improving, his lawyers have vigorously fought the government's efforts to medicate him.
At one point, a federal appeals court halted the forced medication, but resumed it once mental health experts at the prison concluded that Loughner's condition was deteriorating further.
Loughner has demonstrated bizarre behavior since his arrest.
He was removed from a May 25, 2011, court hearing when he lowered his head to within inches of the courtroom table, then lifted his head and began a loud and angry rant.
His psychologist has said that since Loughner has been forcibly medicated, his condition has improved. He sat still and expressionless for seven hours at a hearing in September 2011.
Fox News' Mike Levine and The Associated Press contributed to this report.