Bombers aimed for July 4 but worked too fast Washington: The surviving suspect in the Boston Marathon bombings told FBI interrogators he and his brother had considered suicide attacks and striking on the Fourth of July as they plotted their deadly assault, two law enforcement officials said. But the suspect, Dzhokhar Tsarnaev, 19, told investigators that he and his brother, Tamerlan, 26, who was killed in a shootout with the police, had ultimately decided to use pressure-cooker bombs and other home-made explosive devices, the officials said. The brothers finished building the bombs in Tamerlan's apartment faster than they had anticipated and so decided to bring forward their attack to the Boston Marathon on April 15, Patriots' Day in Massachusetts, according to the account that Dzhokhar provided authorities. They picked the finish line of the marathon after driving around the Boston area looking for alternative sites. Dzhokhar Tsarnaev has also told authorities that he and his brother viewed the internet sermons of Anwar al-Awlaki, a radical American cleric who moved to Yemen and was killed in September 2011 by a US drone strike. There is no indication that the brothers had communicated with Awlaki. Dzhokhar made his admission on April 21, two days after he was captured while hiding in a boat in a nearby backyard, to specially trained FBI agents who had been waiting outside his hospital room for him to regain consciousness. On Thursday the FBI continued to investigate the role that Tamerlan Tsarnaev's wife, Katherine Russell, might have played in the plot or in helping the brothers evade the authorities after the attacks. They particularly want to find out what Tamerlan and his wife discussed when he phoned her a few hours after the FBI released photos of him and his brother as suspects in the deadly attack, a federal law enforcement official said on Thursday. The content of the phone conversation between Tamerlan and Ms Russell has not been disclosed, but authorities want to discuss it with her, the law enforcement official said. The authorities have also sought to determine whether fingerprints and DNA found on bomb fragments were from Ms Russell. Two other law enforcement officials said Ms Russell's fingerprints and DNA did not match those found. Federal authorities are sceptical of Ms Russell's insistence that she played no role in the attack or in helping the brothers elude the authorities after the FBI released photographs of them. That scepticism has been stoked by Ms Russell's decision in recent days to stop co-operating with the authorities. It had been kept at a Boston facility for more than a week after his death. Terrel Harris, a spokesman for the office of the Chief Medical Examiner of Massachusetts, said a funeral services company retained by the family had claimed the body. No details were given as to the cause of death. New York Times, Bloomberg