(CNN) -- Lawyers for suspected Boston Marathon bomber Dzhokar Tsarnaev have asked a federal court to strike comments he made at a hospital after suffering wounds during a manhunt that paralyzed the city in the days following the 2013 race.
In a motion filed Wednesday, they asserted that authorities repeatedly questioned Tsarnaev, 20, as he begged for rest and requested a lawyer at least 10 times.
Defense attorneys said Tsarnaev was groggy and under the influence of several pain medications after undergoing emergency surgery when FBI agents began questioning him hours after his capture on April 19.
Tsarnaev had suffered several gunshot wounds, including one to the head, according to the motion. His left eye was sutured shut, his jaw was wired closed and he was unable to hear out of his left ear. He was unable to speak after undergoing a tracheotomy, according to the motion.
Unable to respond verbally, Tsarnaev wrote answers to interrogators' questions in a notebook, where his attorneys said he scribbled the word "lawyer" 10 times.
The motion said other notes showed that he also wrote: "Can we do this later?" "I'm exhausted," and "You said you were gonna let me sleep."
Defense lawyers claimed that any comments Tsarnaev made during these interrogations -- which went on intermittently for hours at the hospital -- should be inadmissible in court because they were not given voluntarily.
Government officials have indicated that Tsarnaev was questioned under what is called the "public safety" exception to the Miranda warnings, which allows for limited questioning by law enforcement of a suspect to determine if there is imminent danger to the public of an attack.
But defense lawyers said Tsarnaev told police after being captured that he had discarded his gun and where it could be found.
Tsarnaev is accused of planting the bombs at the finish line of the 2013 race, along with his brother Tamerlan, who was killed during the manhunt.
His trial is set for early November, with the government seeking the death penalty.
Defense lawyers are expected to argue the younger Tsarnaev was under the "domination and control" of his brother.
In a separate motion on Wednesday, the defense asked the court to declare the death penalty unconstitutional, calling the practice "cruel and unusual."
The defense listed several objections to the Federal Death Penalty Act, including "public and worldwide revulsion over the recurring spectacle of botched executions."
Lawyers specifically pointed to the case of Clayton Lockett, a convicted murderer who died in April of an apparent heart attack almost 45 minutes after his execution began at Oklahoma State Penitentiary. Authorities said one of his veins collapsed during the administration of a previously unused combination of lethal injection drugs.
Defense lawyers also argued the federal government's authority to impose the death penalty should be limited because it is illegal in Massachusetts, where Tsarnaev's trial is scheduled.
In seeking the death penalty, prosecutors cite as an aggravating factor Tsarnaev's "betrayal of the United States." They claim that after receiving asylum from the United States, he "enjoyed the freedoms of a United States citizen; and then betrayed his allegiance to the United States" by killing and maiming its people.
Defense attorneys also requested in a separate motion that prosecutors turn over instructions given to the grand jury that indicted Tsarnaev.
The lawyers hope to determine whether jurors knew that some findings would be used in the prosecution's pursuit of the death penalty.
They argued that this point is particularly significant because the jury was made up of Massachusetts citizens. The state banned the death penalty in 1984.
At the time the grand jury was considering its indictment, prosecutors had not publicly revealed their intention to seek the death penalty.