In his first comments since the acquittal of George Zimmerman in the Martin case, the attorney general said the 17-year-old's death provides an opportunity for the nation to speak honestly about complicated and emotionally charged issues.
He said the nation must not forgo an opportunity toward better understanding of one another.
On Sunday, the Justice Department said it is reviewing evidence in the case to determine whether criminal civil rights charges would be brought.
The department opened an investigation into Martin's death last year but stepped aside to allow the state prosecution to proceed.
Holder said, "We are ... mindful of the pain felt by our nation surrounding the tragic, unnecessary shooting death of Trayvon Martin in Sanford, Fla., last year." The attorney general's characterization of the killing drew strong applause from the audience at the 51st national convention of the Delta Sigma Theta, the nation's largest African-American sorority.
"Independent of the legal determination that will be made, I believe that this tragedy provides yet another opportunity for our nation to speak honestly about the complicated and emotionally charged issues that this case has raised," Holder said.
"We must not — as we have too often in the past — let this opportunity pass," he added.
"I hope that we will approach this necessarily difficult dialogue with the same dignity that those who have lost the most, Trayvon's parents, have demonstrated throughout the last year — and especially over the past few days," said Holder. "They suffered a pain that no parent should have to endure — and one that I, as a father, cannot begin to conceive."
The Justice Department says the criminal section of the Justice Department's civil rights division, the FBI and federal prosecutors in Florida are continuing to evaluate the evidence generated during the federal investigation, plus evidence and testimony from the state trial.
The NAACP and others are calling on the Justice Department to file civil rights charges against Zimmerman. Thousands of demonstrators from across the country protested the jury's decision to clear Zimmerman in the shooting death of the unarmed black teenager.
Also on Monday, the White House said President Barack Obama won't involve himself in the Justice Department decision on whether to pursue civil rights charges against Zimmerman. White House spokesman Jay Carney said it would be inappropriate for Obama to express an opinion on how the department deals with Zimmerman.
AP reporter Ben Nuckols contributed to this report.
Copyright 2013 The Associated Press.