While rare, it is not unprecedented for a defendant who was not the "triggerman" to be found guilty of capital murder and sentenced to death. In the case of Muhammad, the first of the two suspects in last fall's sniper shootings to stand trial, legal experts say defense attorneys faced a particularly difficult task in convincing jurors that he was somehow less culpable than his teen-age companion, Lee Boyd Malvo.
"If somebody's the mastermind, you might say they are the principal actor, even if they didn't pull the trigger," said Welsh S. White, a University of Pittsburgh law professor. "But that's the best shot he has - to say, 'I didn't do it. It was the other guy.'"
To find Muhammad guilty of capital murder under the first count, the jury must determine that Muhammad was an "immediate perpetrator" of the offense. Under the terrorism law, which is being tested before a jury for the first time since it was enacted after the Sept. 11, 2001, attacks, jurors can convict Muhammad of capital murder if they find that he directed or ordered Malvo during the sniper attacks.
Defense attorneys have argued that Muhammad should face, at worst, a first-degree murder conviction because the government's evidence did not show that he fired the bullet that killed Dean H. Myers at a Prince William County gas station on Oct. 9, 2002. A first-degree murder conviction would carry a maximum penalty of life in prison.
But Judge LeRoy F. Millette Jr. refused this week to take the death penalty off the table.
Ruling outside the jury's presence, Millette said Wednesday that there was strong evidence that Muhammad was a principal in the first degree in Myers' death, meaning that he had a primary role in the killing, even if he did not pull the trigger.
Higgs was convicted in U.S. District Court in Greenbelt of ordering the murders of three women on federal parkland in Maryland in 1996 and became the first Maryland inmate on federal death row, even though prosecutors never argued that Higgs did the shooting.
At an earlier trial, a jury had rejected the federal death penalty for convicted triggerman Willis Mark Haynes, who was sentenced to a term of life plus 45 years.
In Higgs' case, which followed, Sullivan said not a single juror was swayed by the fact that the man who pulled the trigger had received a lesser sentence. He saw other problems as well for Muhammad's lawyers.
"When you're trying to say that someone else who is much younger was more culpable, that's really hard to sell. ... I don't think that regular jurors are going to see that, because it defies common sense," Sullivan said.
Simply because Muhammad was older and bigger than Malvo does not make him the mastermind, Greenspun said, arguing that prosecutors had presented little evidence about the interplay between the two men.
"You know nothing about the relationship between Mr. Muhammad and Mr. Malvo," Greenspun said. "They want you to believe in your heart of hearts, even though the evidence doesn't support it, that Mr. Muhammad somehow instructed Mr. Malvo."
University of Maryland law professor Michael A. Millemann said Virginia Supreme Court decisions about the issue of principal in the first degree leave room for defense attorneys to argue on appeal that Muhammad was not guilty of capital murder. But that doesn't mean it would be an easy sell, he said.
"There's still room to argue it - even if a jury convicts - there's still a plausible argument on appeal that he's not guilty of capital murder," Millemann said. "But it's hard. It's hard to imagine a worse case to test how far first principalship extends."
Millemann said Muhammad's decision to act as his own lawyer early in the case, even if only briefly, could haunt him now as jurors weigh the question of whether he was, as prosecutors contend, the captain of the killing team.
"They're saying, 'Here's the guy in charge,' and, 'Well, look, he just fired his lawyers and he's representing himself,'" Millemann said.