Dzhokhar Tsarnaev's lawyers have been trying to paint him as a gullible teen who was recruited by his extremist brother to bomb the Boston Marathon finish line two years ago. But today, prosecutors presented the jury with a never-before-seen photo that tells quite a different story. Seen in the bedroom of his family home in Cambridge, Massachusetts, Dzhokhar Tsarnaev sits at a computer chair and points to a black flag behind him - not unlike the kind used by extremist groups like al-Qaeda and ISIS. Tsarnaev's former best friend Stephen Silva testified in court on Tuesday that he saw the flag hanging in Dzhokhar's room, the one time he visited the apartment to watch The Walking Dead. Scroll down for video . Decoration: A new picture emerged of Dzhokhar Tsarnaev in court on Tuesday, showing the accused Boston bomber posing underneath a black banner of Islam in the bedroom of his Cambridge family home . Silva was also the friend who lent Tsarnaev the gun used to shoot an MIT police officer in a confrontation a few days after the bombings. While the so-called Black Banner or Black Standard has been co-opted by Islamist extremist groups in recent years, it has much deeper origins in the Muslim world. The prophet Muhammed used a black standard when he fought, which is why it continues to be used as a symbol for modern-day jihadists. According to Boston University master Arabic lecturer Giselle Khoury, the flag reads: 'There is no god but Allah, and Muhammad is Allah's Messenger'. She told the Boston Herald that the statement is called 'the shahada - the testimony' which declares one's belief in the Islamic faith. However, quickly after the picture of the flag was shown in court today, U.S. District Court Judge George A. O’Toole Jr ordered taken out of court since he found it 'illegible'. Assistant U.S. Attorney Aloke Chakravarty said another witness, who did not take the stand today, would be explaining the flag's significance further. Tsarnaev, 21, is charged with killing three people and injuring 264 with a pair of homemade pressure-cooker bombs at the race's crowded finish line on April 15, 2013, and shooting dead a university police officer three days later. Where the Boston Bombing was hatched: The jury deciding the federal death penalty trial were also shown other pictures from the Tsarnaev family home, including the image of the right of Dzhokhar's home computer . Authorities release this picture of the flag - which has become a symbol of Islamic terror groups the world over since the 1990s . Where he slept: Dzhokhar's former best friend Stephan Silva says they were friends for several years, but that he only visited the Tsarnaev house once to watch an episode of The Walking Dead on a computer from the top bunk of Dzhokhar's bunk-bed (above) Strict older brother: Silva told the court on Tuesday that he had never met his elder brother Tamerlan (left) and that Dzhokhar (right) described him as 'very strict, very opinionated' His former best friend Stephen Silva, who federal prosecutors contend loaned . Tsarnaev the gun used in the shooting, testified in court on Tuesday that he had long been close with the defendant but had never met his 26-year-old . brother, Tamerlan, who died following a gunfight with police . four days after the bombing. He said his brother was very strict, very opinionated, and . that since I wasn't a Muslim he might give me a little s*** for . that,' Silva said. Defense lawyers opened the trial at U.S. District Court in . Boston with the blunt admission that Dzhokhar Tsarnaev had . carried out the crimes he is charged with, focusing their hopes . on the jury sentencing him to life in prison rather than the . death penalty he could face if found guilty. They contend Tamerlan was the driving force behind the . attacks and that his younger sibling followed out of . subservience. Convict friends: Friend of Dzhokhar Tsarnaev, Stephen Silva (left), testified at the Boston bombing trial on Tuesday about his 'strict' older brother Tamerlan. He is currently in jail on weapons and drug charges. Tsarnaev and Silva pictured on the right at their high school graduation . Prosecutors called Silva, 21, to the witness stand to . discuss the loan of the rusty Ruger P95 handgun they contend was . used to shoot dead Massachusetts Institute of Technology police . officer Sean Collier on April 18, 2013. Silva has pleaded guilty to federal gun and drug charges, . but was offered leniency in exchange for his testimony. He . testified he had gotten the gun from a friend, intending to use . it to protect his drug business, and also used it in a robbery. Tsarnaev asked to borrow it, saying he too was interested in . committing a robbery, Silva testified. On loan: The gun was part of evidence shown in court on Tuesday. Friend of Dzhokhar Tsarnaev, Stephen Silva,  allegedly gave him the weapon which was used to kill MIT officer Sean Collier . Ruined: This smashed-up iPhone was found at the scene of a shootout between the Tsarnaev brothers and police in the suburb of Watertown on April 18 - a few days after the bombings . In the most aggressive cross-examination by the defense in . eight days of testimony, Silva acknowledged having posted on . Facebook and having told the FBI that he believed the bombing must have been Tamerlan's idea. 'At the time that's what I felt, yes,' Silva said in . response to questioning by defense attorney Miriam Conrad. He also acknowledged having told prosecutors in August he . used 'peer pressure' to persuade Dzhokhar to smoke marijuana, . which Silva sold. 'That's what I said but I stated it wrong,' Silva said on . Tuesday. Emerging: Boston Marathon bomber Dzhokhar Tsarnaev, bloody and disheveled with the red dot of a sniper's rifle laser sight on his head, emerges from a boat at the time of his capture by law enforcement authorities in Watertown, Massachusetts on April 19, 2013 . Hide-out: In this courtroom sketch, the boat in which Dzhokhar Tsarnaev was captured was depicted on a trailer for observation during Tsarnaev's federal death penalty trial on Monday . In court: In this courtroom sketch, Tsarnaev, center seated, is depicted between defense attorneys while the boat in which he was captured in sits on a trailer for observation during his federal death penalty trial on Monday . Message: Inside the boat where Dzhokhar Tsarnaev hid for hours before he was captured by police, he carved on wood panels the phrase: 'Stop killing our innocent people and we will stop' Inscription: Another picture of the wood panels taken from inside Henneberry's boat . Silva also testified that Dzhokhar Tsarnaev had once called . him a 'kafir,' an Arabic word meaning non-believer or infidel, . in response to Silva calling the defendant a 'Russian refugee'. Tsarnaev is an ethnic Chechen whose family moved to the . U.S. a decade before the attack. Other than the 'kafir' incident, Silva said Tsarnaev had . rarely talked about religion. Also on Tuesday, the owner of the boat where Tsarnaev hid . after a gunfight with police recalled stepping into his backyard . after a day-long lock down was lifted and finding a person in his . watercraft. David Henneberry described waking up the morning after a . gunfight between the Tsarnaev brothers and police rocked his . suburban neighborhood and noticing something wrong about the . winter covering of his boat, but presuming it had been blown . around by the wind. He put off checking it until after authorities had lifted a . shelter-in-place order on Boston-area residents four days after . the bombing, WBZ reported. 'I went to check on the boat and basically see why the strap . was loose and I noticed a lot of blood,' Henneberry said. 'I . just kept fixating on this blood and then, I just, my eyes . looked at the other side of the boat and that's when I saw a . body in the boat ... I got off the ladder pretty quick and went . in the house.' When prosecutors wrap up their case it will be the defense's . turn to call witnesses, who could include Tsarnaev. After that, . the jury will consider Tsarnaev's guilt. If he is found guilty, . a second phase will play out that will focus on sentencing. The bombing killed restaurant manager Krystle Campbell, 29, . graduate student Lingzi Lu, 23, and 8-year-old Martin Richard. Henneberry said after he called 911, bringing dozens of . heavily armed police who fired scores of rounds into the boat . where Tsarnaev was discovered. The jury also saw two wooden slats from the boat into which . a message had been carved which read: 'Stop killing our innocent . people and we will stop.' On cross-examination, Mr Henneberry was asked by the defense if the blood and bullet holes in his boat were there before April 19. He confirmed that they were not. Final words: Inside the boat, Tsarnaev wrote a series of notes, which the jury saw on Monday. This note, punctured with bullets, explains how he is jealous of his brother Tamerlan because he had died and gone to paradise . The notes also denounced the U.S. for its wars in Muslim countries. Last week, the jury heard how all the bullets that made holes in the side of the boat were shot from outside the vessel as he hid inside . Investigators on a boat in Watertown, Massachusetts the day after Dzhokhar Tsarnaev was found hiding inside in April 2013. On Monday, the jury in his death penalty trial visited the boat .
New picture emerged on eighth day of the federal death penalty trial . Man who found Dzhokhar Tsarnaev hidden in parked boat in Watertown, Massachusetts testified before jury on Tuesday . David Henneberry testified that he found the bomber inside 'not moving with a lot of blood' after he noticed the cover on his boat had come loose . Tsarnaev's former best friend Stephen Silva also told court how he lent him gun used to murder MIT police officer . Silva says Dzhokhar warned him about his 'strict Muslim' brother Tamerlan . Dzhokhar Tsarnaev, 21, faces death penalty if he is convicted of detonating bombs, killing three people and injuring 264 before shooting dead a cop .