BOSTON --Minutes after twin explosions ripped through the Boston Marathon finish line killing three people, one of the accused bombers allegedly told a friend that he wasn't to blame.
"Don't go thinking it's me you cooked bastard," Dzhokhar Tsarnaev texted to college friend Azmat Tazhayakov an hour and a half after the April 15, 2013 bombings in what is the earliest known denial by Tsarnaev, according to prosecutors.
It would take three days for the FBI to release surveillance photos of Tsarnaev and his older brother - both then unidentified -- as suspects in the bombing. A wounded Tsarnaev wasn't captured by police until April 19, hours after his brother, Tamerlan, was killed in a police shootout in a sleepy Boston suburb.
Dzhokhar Tsarnaev allegedly wrote an anti-American screed on the wall of a boat in which he was hiding in the last hours until he was captured, and in a partially redacted court filing, prosecutors said he "readily admitted" to his involvement in the blasts once in custody. However, Tsarnaev has pleaded not guilty to 30 charges relating to the marathon attack, including the alleged use of a weapon of mass destruction.
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Prosecutors made the new claim about the text message today in opening arguments for the trial of Tazhayakov, who, along with two other of Tsarnaev's friends, has been charged with obstruction for allegedly removing evidence from Tsarnaev's dorm room after the bombing. Tazhayakov has pleaded not guilty and his defense attorney told jurors his client had nothing to do with tossing a backpack with fireworks and a laptop from Tsarnaev's apartment into a dumpster as the government claims.
Prosecutors said Dzhokhar Tsarnaev and Tazhayakov spent "every day" after the bombing together before Tsarnaev was arrested.
They also said Tsarnaev had bragged to Tazhayakov a month before that he knew how to build a bomb. But Tazhayakov's defense attorney said that Dzhokhar "never told my client 'I'm going to bomb the Boston Marathon.'"
Prior to the bombing, prosecutors said Tsarnaev and Tazhayakov ate together in a restaurant not far from their college campus when the subject of martyrdom came up.
"It was good to die with a smile on your face and go straight to heaven," Tsarnaev allegedly said then.
Michele McPhee is a Boston-based freelance reporter and frequent contributor to ABC News.