Dias Kadyrbayev (DY'-us kah-dur-BY'-ehv) texted Tsarnaev shortly after photos of Tsarnaev and his brother were released publicly by the FBI as suspects in the deadly attack.
Tsarnaev responded that he had seen the news then texted, "Better not text me my friend," then "Lol." Another text told Kadyrbayev he could go to Tsarnaev's room and "take what's there" followed by a smiley face.
Some of the messages had been released previously but a complete transcript of Kadyrbayev's text messages in the days after the bombing was released by prosecutors Thursday.
Kadyrbayev and two others face charges stemming from the bombing investigation, but are not accused of participating in or knowing about the plot. A judge said Thursday statements the other two men made to investigators can be used at trial.