PHILADELPHIA, Miss. – The reputed Ku Klux Klansman charged with the 1964 murders of three civil rights workers was freed yesterday on $250,000 bail.

Circuit Judge Marcus Gordon set a March 28 trial date for Edgar Ray Killen, arrested in one of the most notorious crimes of the civil rights era.

Mr. Killen left jail with family members, exchanging his orange jumpsuit for a blue plaid shirt, pants, and a brown Western-style hat.

The 79-year-old part-time preacher was arrested last week, the first person to be charged with murder by the state of Mississippi in the killings that focused national attention on the civil rights struggle in the South.

James Chaney, a 21-year-old black Mississippian, and two white New Yorkers, Andrew Goodman, 20, and Michael Schwerner, 24, were ambushed, beaten, and shot. They were helping blacks register to vote during the Freedom Summer of 1964.

Nineteen men, including Mr. Killen, were indicted on federal charges in the case in the 1960s. Mr. Killen’s case ended in a hung jury, but seven others were convicted in 1967 of violating the victims’ civil rights. None served more than six years.

Prosecutors have refused to detail the evidence against Mr. Killen in the new case. According to FBI files and evidence from the federal case, Mr. Killen allegedly organized the carloads of Klansmen who hunted down the civil rights workers.

District Attorney Mark Duncan did not oppose the setting of bail because he would have had to demonstrate an overwhelming presumption of guilt and show that Mr. Killen might flee or pose a danger to the community. “It would require me to put on evidence and show my hand,” Mr. Duncan said.

Mitch Moran, a lawyer for Mr. Killen, questioned the 40-year delay in bringing charges. “It was an awful crime, and if the evidence was there 40 years to indict Mr. Killen … my question is: Why was he not indicted?” Mr. Moran asked. “Is this in the interest of justice or is this political?”