Tsarnaev had second Twitter account, tweeted praise for Anwar al-Awlaki, FBI agent testifies

Weeks before allegedly planting one of two bombs at the finish line of the 2013 Boston Marathon, Dzhokhar Tsarnaev created a second Twitter account where he tweeted praise for the late American-born al-Qaeda leader Anwar al-Awlaki, an FBI agent testified at Tsarnaev's trial Monday.

"Listen to Anwar al Awlaki's (a shaheed iA) the here after series," Tsarnaev, tweeting under the name Ghuraba (@Al_firdausiA), wrote on March 11, 2013. "You will gain an unbelievable amount of knowledge #islam #muslim."

Before his arrest, Tsarnaev was active on Twitter, joining the social media network in 2011 under the handle @J_tsar.

As was widely reported after he was identified as a suspect in the case, Tsarnaev's public tweets were relatively benign — a mix of rap lyrics and college-level observations — with occasional hints at darkness.

This tweet, published by Tsarnaev roughly a year before the marathon attack, translates as "I will die young," FBI agent Steve Kimball told jurors.

Immediately following the bombings, Tsarnaev posted several messages, some of them cryptic.

Prosecutors are seeking to show that private messages Tsarnaev sent to users — along with tweets from the second account — prove the then 19-year-old was becoming radicalized on his own.

Three people died and more than 260 others were injured when two bombs exploded at the finish line. Tsarnaev, 21, is accused of plotting and carrying out the twin bombings along with his older brother, Tamerlan, who was killed during a confrontation with police four days after the attacks. The brothers are also accused of shooting and killing a Massachusetts Institute of Technology police officer while on the run from the authorities. Tsarnaev, who has pleaded not guilty, faces the death penalty if convicted.

Al-Awlaki was killed in a U.S. drone strike in Yemen in 2011.

Earlier Monday, government witnesses, including victims and first responders, described the carnage they saw after the bombs exploded.

"We shifted into mass casualty mode," Boston EMS chief James Hooley testified.

Jessica Kensky, who lost both legs as a result of the attacks (her husband lost one) and took the stand in a wheelchair, recalled "shielding her husband from the sight of his mangled leg" and "being pushed to the ground as a bystander frantically tried to extinguish the flames on her body."

“This was a war zone, something I had never seen before," Kensky said.

Danling Zhou, who attended the marathon with Lingzi Lu, and a doctor who treated them at the scene described Lu's horrific injuries — and her last breaths.

Lu’s leg had been "splayed" open from the pelvis to the ankle, Dr. James Bath said: “All of her blood was on the sidewalk."

About 20 minutes after the bombs went off, Tsarnaev was seen on surveillance video at a Cambridge Whole Foods buying milk, the store's assistant manager, Caitlin Harper, testified.

Two minutes later, he returned to exchange it.