( CNN ) -- Lawyers for Boston Marathon bombing suspect Dzhokhar Tsarnaev asked a federal court Thursday to strike his alleged `` betrayal '' of the United States as an aggravating factor for seeking the death penalty against him . A defense motion accused prosecutors of trying to use the suspect 's foreign birth and immigration to imply that Tsarnaev is `` more blameworthy , and more deserving of severe punishment '' than a native-born person who commits the identical crime . `` The 'betrayal ' factor has no legally permissible role in this case , and can only serve to promote invidious discrimination based on national origin and immigration status , '' the defense motion said . The Tsarnaev family originally came from Chechnya , a war-torn corner of southwestern Russia where Islamist guerrillas have been battling government forces for a decade and a half . Dzhokhar Tsarnaev and his older brother Tamerlan Tsarnaev were born in Kyrgyzstan . Dzhokhar had become an American citizen , while Tamerlan 's application was still pending when the bombing occurred . Dzhokhar Tsarnaev , 20 , is accused of planting the bombs at the finish line of the 2013 race , along with Tamerlan , who was killed during the manhunt that paralyzed Boston . The city marked the anniversary of the attacks on April 15 , pausing to remember the three people who died and the more than 200 who were wounded , many of whom lost limbs . The trial is set for early November , with the government seeking the death penalty . Defense lawyers are expected to argue that the younger Tsarnaev was under the `` domination and control '' of his brother . `` Resentment of Tsarnaev 's immigration status and history is perhaps natural , given the nature of the crimes charged , and it is surely very widespread , '' Tsarnaev 's lawyers said in the motion . `` But the fact that he had only recently become a citizen , standing alone , does not increase his moral or legal guilt , and it should not be permitted . '' In the notice to seek the death penalty , prosecutors said : `` Dzhokhar Tsarnaev received asylum from the United States ; obtained citizenship and enjoyed the freedoms of a United States citizen ; and then betrayed his allegiance to the United States by killing and maiming people in the United States . '' On Wednesday , federal prosecutors filed court papers asking that the family visits of the jailed suspect be monitored to ensure they are not used to convey hidden messages , according to court documents . Prosecutors said Tsarnaev 's conversations with his mother , now in the Russian republic of Dagestan , have raised the possibility that the defendant might use social visits `` to communicate with third parties . '' In phone calls with him , his mother twice mentioned that she had contact with close friends of Tamerlan Tsarnaev , according to prosecutors . In a hearing last month , U.S. District Judge George O'Toole appeared to side with the defense argument that visits between Tsarnaev and his sisters should not be monitored by the FBI . Defense lawyer David Bruck argued that letting federal agents monitor the conversations intruded on the defense . `` The decision to take the most casual remarks , an ironic comment , and provide it to the prosecution ... becomes ammunition on the death penalty , '' Bruck said . If the charges against Tsarnaev are true , he said , `` This is about a family , '' and lawyers should be allowed to observe the relationship between the siblings without interference . In Wednesday 's court filing , Assistant U.S. Attorney Nadine Pellegrini said some of Tsarnaev 's telephone conversations while in prison `` have raised the possibility he might seek to use social visits to communicate with third parties . '' O'Toole has said he would make a decision after considering the prosecution 's response . Separately , Tsarnaev 's defense team expressed concern about its ability to be `` adequately prepared '' for the November 3 trial date . In another motion , defense attorneys said they need more information from the government 's investigation into the explosive device and other forensic evidence . `` It can not be ignored that the aggressive timeline for bringing this complicated and multifaceted case to trial dramatically compresses the time available for the defense to adequately prepare for trial , '' attorneys Judy Clarke and David Bruck wrote .
Defense seeks to strike Tamerlan `` betrayal '' as reason for death penalty . Prosecutors want to monitor O'Toole family visits . Tsarnaev , early November , is accused of planting bombs at the finish line of the early November Boston Marathon . His trial is set for early November , with the government seeking the death penalty .