With the deaths of veteran activists, so goes a measure of passion to pursue justice in unsolved murders of the Civil Rights era.

Today’s advocates now wonder how many of the numerous unsolved civil rights cases will be prosecuted.

“If advocates are not there to push it, prosecutors may not be inclined to do it. Many of the cases weren’t investigated to begin with,” said Penny Weaver of the Southern Poverty Law Center in Montgomery, Ala.

FBI Director Robert Mueller, whose agency this year launched an initiative to review bloody crimes of the era, acknowledged the difficulty of solving the cases as witnesses die and memories fade.

The recent death of civil rights pioneer C.C. Bryant had a sobering effect on Derrick Johnson, president of the NAACP in Mississippi, where dozens of blacks lost their lives or were beaten and jailed as they fought for equal rights in the segregated South.

Bryant, who was 90 when he died at his McComb home on Sunday, had worked with the Student Nonviolent Coordinating Committee to launch a voter registration drive in 1961.

Another civil rights veteran who died this year was June E. Johnson, a Greenwood native, who as a teenager was arrested alongside Fannie Lou Hamer and others as they traveled to a voter registration workshop in South Carolina.

June Johnson and Bryant were contemporaries of Aaron E. Henry and Medgar Evers, two deceased NAACP leaders active in the 1950s to 1970s. Evers, who was field secretary for the organization, was killed outside his home in 1963. Self-proclaimed white supremacist Byron De La Beckwith was convicted of the crime 30 years later and died in prison.

Henry, who led the state NAACP for 33 years, died in 1997. In the 1960s, Henry’s house and business were firebombed for his civil rights activism and he was arrested 30 times. As a punishment for one protest, he was chained to a garbage truck and driven through the streets of his Mississippi Delta hometown of Clarksdale.

For some, such passion for social change, to sacrifice personally for commitment to a cause is disappearing as rapidly as the men and women who became the faces of the Civil Rights Movement in the 1950s and 1960s.

“With the passing of icons such as C.C. Bryant, we lose a library of activity that took place during the civil rights era,” Johnson said.

Hollis Watkins, a 66-year-old activist who worked alongside Bryant in McComb, said he can’t say he’s encouraged by the FBI initiative.

“When they are trying to get to the bottom of these cases, to me they’re just doing their jobs. If a person starts to do his job, that’s good,” said Watkins. “I don’t think it has reached the point where I can say it’s encouraging.”

Watkins said his justice organization, Southern Echo, recruits young people to assist in its work to boost voter education and registration.

“By us providing that kind of information to younger people, if by chance, older ones of us pass off the scene, the importance of those cases being reopened still remains among the general public,” said Watkins, who was once jailed for participating in a sit-in at a Woolworth counter in McComb.

The Southern Poverty Law Center’s research of civil rights crimes found 74 men and women who died between 1962 and 1968 in the South. Weaver said those names were turned over to the FBI.

The FBI hasn’t publicly identified which cases are under review.

The 1964 murders of three civil rights workers in Mississippi isn’t believed to be among them. A jury in 2005 convicted of Edgar Ray Killen of manslaughter in the deaths of Michael Schwerner, James Chaney and Andrew Goodman.

Killen was among several others tried in 1967 on federal charges of violating the victims rights. The all-white jury deadlocked in Killen’s case, but seven others were convicted. None served more than six years.

The NAACP and others have called for the case to be reopened again, claiming there are six others still alive who should face charges in the case. Attorney General Jim Hood has said a lack of evidence and witnesses have prevented any more prosecutions.