San Diego criminal defense attorney Judy Clarke has the "background, knowledge and experience" that will "enable her to provide adequate representation" to suspect Dzhokhar Tsarnaev, U.S. Magistrate Judge Marianne Bowler said in a ruling.
Clarke will join three other public defenders -- Miriam Conrad, Massachusetts' chief federal public defender, and two assistant public defenders -- in defending Tsarnaev, 19, who faces charges of using a weapon of mass destruction and malicious destruction of property resulting in death.
He and his older brother, Tamerlan, are accused in the April 15 bomb attacks near the marathon finish line that killed three people and injured more than 260.
They also allegedly killed a Massachusetts Institute of Technology police officer.
Tamerlan Tsarnaev, 26, died after a police shootout early April 19. Police say they were subduing him when his brother ran him over in a stolen car in a desperate escape.
Clarke, who had no immediate comment on her appointment, has served as a public defender in many high-profile U.S. cases.
She defended Loughner, who was spared the death penalty last year by pleading guilty to 19 charges of murder and attempted murder in 2011's Tucson shooting rampage that killed six people and wounded 13, including Rep. Gabrielle Giffords, D-Ariz.
She also defended Kaczynski, who avoided the death penalty in 1998 by pleading guilty to all the government's charges associated with his 17-year nationwide bombing campaign against modern technology that killed three people and injured 23 others. Kaczynski is designated a "domestic terrorist" by the FBI.
Clarke's clients also included convicted Islamic terrorist Zacarias Moussaoui, who pleaded guilty to helping plan the Sept. 11, 2001, terrorist attacks -- the only person tried in a U.S. court on charges of involvement in the attacks -- and convicted child murderer Susan Smith, who drowned her two young sons Oct. 25, 1994, so she could resume an affair with a wealthy man who had no interest in a "ready-made" family.
Both of those Clarke clients are also serving life sentences.
The Boston Globe cited Bowler as writing: "A federal death penalty case implicates particular procedural requirements and 'is extremely demanding to defend because of the effort and pressure involved.' In light of the circumstances in this case, the defendant requires an attorney with more background, knowledge and experience in federal death penalty cases than that possessed by current counsel.
"Appointment of Attorney Clarke is therefore justified to provide the defendant with adequate and proper representation," Bowler wrote.
After Dzhokhar Tsarnaev was charged last week, the defense asked Bowler for two lawyers "learned in the law applicable to capital cases," the Globe said.
In her ruling Monday, Bowler denied, at least for now, the request for death-penalty specialist attorney David I. Bruck to join the defense team.
Bruck teaches law at Washington and Lee University law school in Lexington, Va., and directs the school's death-penalty defense clinic.
Bowler said Clarke's "qualifications demonstrate she is 'learned in the law' of capital cases."