(CNN) -- Federal prosecutors say that Tucson shooting defendant Jared Lee Loughner should be involuntarily medicated because he poses a danger, according to court records filed with a federal appeals court.
U.S. Attorney Dennis Burke of Arizona said Loughner uttered a profanity and threw a chair twice toward a doctor while in custody in March; spat on his attorney, lunged at her and had to be restrained by staff in April; and threw chairs in his cell in May.
Loughner has been diagnosed as a schizophrenic, Burke said.
"After seeing the defendant's aggressive conduct, and knowing that he has been charged with murder and violent offenses, prison officials had a 'duty to ensure the safety of prison staff and administrative personnel' who are interacting with the defendant...," Burke wrote in court papers.
Prison officials "properly determined that the defendant could be medicated involuntarily," Burke said in court documents.
The federal government had a Wednesday deadline to argue that the forced medication should continue.
A federal appeals court in San Francisco temporarily halted the medication until a three-judge panel can hear competing arguments from his lawyers and prosecutors by the middle of this week.
Loughner is charged with killing six people in a supermarket parking lot in Tucson, Arizona, on January 8. Among the 13 people wounded was U.S. Rep. Gabrielle Giffords, D-Arizona, who was shot in the head.
The brief order from a three-judge panel of the 9th Circuit U.S. Court of Appeals, made public Tuesday, set a tight deadline for lawyers from both sides to file more detailed legal briefs.
Loughner's lawyers had appealed Friday an earlier ruling allowing prison doctors to forcibly medicate him with strong drugs.
The appeals judges will decide whether to issue a permanent order that could extend the ban on forced medication, or allow the procedure to resume. There was no indication how soon the panel would rule.
Last week, a federal judge in San Diego rejected a motion by lawyers for Loughner to prevent prison doctors from forcibly medicating the Arizona shooting suspect.
"I defer to medical judgment," U.S. District Judge Larry Alan Burns said in ruling that prison doctors were within their rights to force Loughner to take mind-altering psychotropic drugs against his will. "I have no reason to disagree with the doctors here."
Burns also ordered that sensitive medical and legal documents relating to Loughner's treatment for mental illness remain sealed.
Loughner has already started receiving the powerful drugs, and lawyers representing Loughner contend that forcing him to take the drugs against his will violates his rights.
Authorities at the U.S. Medical Center for Federal Prisoners in Springfield, Missouri, where Loughner is being held, should have tried lesser restraints such as milder tranquilizers, argued Reuben Camper Cahn, one of Loughner's lawyers.
Prosecutors responded in last week's hearing that prison officials acted properly in ordering the medication, which they said was necessary for Loughner to control his mental illness.
"This is a person who is a ticking time bomb," prosecutor Wallace Kleindienst said. "He's lunged at his defense counsel and spits at her."
Loughner, 22, is charged in the January mass shooting in which six people were killed and 13 wounded, including Giffords, in front of a Safeway grocery story in Tucson, Arizona.
A federal judge ruled last month that Loughner was not competent to stand trial, and he was sent to the federal facility in Springfield.
Loughner's lawyers said prison officials held a deficient hearing process and used faulty reasoning in deciding to drug Loughner against his will.
For example, Loughner had no attorney present at the June 14 hearing, the lawyers said in their motion, and officials failed to state the drug and dosage he should receive.
According to the emergency motion filed last month, authorities had earlier assessed Loughner as dangerous because of incidents before his transfer to the Springfield prison: He threw a chair against a door and spat at an attorney.
However, the reasoning by prison officials in Springfield for deciding to administer the drugs was to treat Loughner's mental illness, rather than to subdue any dangerous behavior, the motion said.
Prosecutors had argued in their response that Loughner received a proper administrative hearing on the matter, and the medication prescribed was necessary to prevent him from being a danger to himself and others.
CNN's Bill Mears contributed to this report.