On Tuesday, the former friend of Boston Marathon bombing suspect Dzhokhar Tsarnaev gave a chilling testimony about Tsarnaev's behavior in the days after the attack.

Azamat Tazhayakov, a 20-year-old native of Kazakhstan, revealed that the suspected bomber remained calm and normal after he allegedly planted two bombs at the marathon's finish line on April 15, 2013. According to Tazhayakov, Tsarnaev sent him a text message about an hour after the pressure-cooker bombs exploded, which read: "Don't go thinking it's me, you cooked bastard," reports the Boston Globe.

Tazhayakov is one of three of Tsarnaev's friends at the University of Massachusetts Dartmouth who are accused of interfering with the bombing investigation. He is the first former UMass Dartmouth student to stand trial, while the other two former students, Dias Kadyrbayev and Robel Phillipos, will also face an obstruction of justice trial.

Like Tazhayakov, Kadyrbayev is also accused of going to Tsarnaev's dorm room on April 18 and "seizing and discarding Tsarnaev's backpack, which contained manipulated fireworks," reports the Globe. Meanwhile, Phillipos is accused of lying to investigators about his whereabouts that night.

During Tazhayakov's trial, prosecutors portrayed both he and Kadyrbayev as hard-partying students who felt the need "to protect their close friend Dzhokhar Tsarnaev," rather than help law enforcement identify and stop the suspects.

Tsarnaev's former roommate Andrew Dwinells also gave testimony at the trial, stating that Tsarnaev spent much of his time sleeping, texting and on the computer after the explosion.

"He slept a little bit more, but that was it," Dwinells said, according to the Associated Press.

He also told prosecutors that said he and Tsarnaev didn't talk much or socialize together.

According to Dwinells, Kadyrbayev told him that "he needed to get into the room to get something."

He then took a small bag of marijuana out of a desk drawer and searched the room, while Tazhayakov and Robel Phillipos watched TV.