JACKSON (AP) — Prosecutors in the federal kidnapping and conspiracy trial of James Ford Seale told jurors during opening arguments Monday that they’ll prove the reputed Klansman was among those who abducted, attacked and drowned two black teenagers in 1964.

Defense attorneys, however, said the government’s case will be based largely on a member of the Ku Klux Klan who has changed his story in the 43 years since Henry Hezekiah Dee and Charles Eddie Moore were dumped in the Mississippi River to die.

‘‘Being a member of the Klan, as detestable and abominable as it may be, was not a crime then and is not a crime now,’’ public defender George Lucas said. ‘‘You must remember, my client is not on trial for being a racist. He’s not on trial for murder.’’

Opening arguments took place after attorneys wrapped up four days of jury selection by choosing eight whites and four blacks to hear the case. They also chose three white alternates, including one woman who said her abusive father used to be in the Klan.

About 60 spectators, including members of both Seale’s and the victims’ families, watched the trial unfold. Black-and-white photos of the two 19-year-old victims were displayed on computer screens so jurors and courtroom spectators could see them during opening arguments.

Seale, 71, has denied belonging to the Klan. Wearing a wishbone-shaped hearing aid, he sat expressionless during the testimony of the first three witnesses — two law officers and a funeral home worker who helped pull the bodies of Dee and Moore from a backwater of the Mississippi River two months after the friends disappeared.

Prosecutor Paige Fitzgerald told jurors that Seale and other Klansmen were investigating rumors that Dee was part of a conspiracy to bring guns into southwest Mississippi for a race riot. Seale reported to his father, Clyde Seale, head of the local Klan chapter or ‘‘Klavern,’’ that he had seen Dee walking around the small town of Meadville.

A short time later, Fitzgerald said, two vehicles with Seale and other members of the Klan pulled up behind Dee. By then, Moore was walking with his friend, and both were picked up.

‘‘Charles Moore was just in the wrong place at the wrong time and his skin was the wrong color,’’ Fitzgerald said.

She said Dee and Moore were taken to the Homochitto National Forest, where Seale held a sawed-off shotgun on them while they were beaten. Dee falsely confessed that guns were being held in the Roxie First Baptist Church.

While Klansmen and members of local law enforcement checked the church, where no guns were found, James Ford Seale and others took Dee and Moore to Clyde Seale’s farm. There, James Ford Seale and another Klansman bound the victims with duct tape, put them in a plastic-lined trunk of a car and drove them across the state line into Louisiana, Fitzgerald said. Moore and Dee were weighted down with metal objects and tossed into the river.

The charges of kidnapping and conspiracy against Seale hinge on prosecutors proving the victims were taken across the state line before being killed, Lucas said.

Fitzgerald said a now-retired FBI agent will testify he was present when Seale was arrested in November 1964 and a Highway Patrol officer said he knew Seale took part in the killings. She said Seale told the agent: ‘‘I’m not going to admit it, you’re going to have to prove it.’’

‘‘Well, ladies and gentleman, after 43 years we are here to do just that,’’ Fitzgerald said.

The headless partial bodies of Dee and Moore were found about 70 miles from where they were abducted, near Palmyra Shoot, a body of water where Warren County, Miss., and Madison and Tensas Parishes in Louisiana converge.

Fitzgerald said one of the Klan conspirators owned land on a small portion of Mississippi that’s on the Louisiana side of the river, near where the bodies were found.

John Rogan’s brother, the late James Rogan, was Tallulah police chief in 1964, and prosecutors on Monday showed black-and-white footage of a TV interview the chief did the day the first body was found. The audio was muffled with age, and jurors followed on written transcripts.

John Rogan testified that on July 12, 1964, he was six days shy of his 20th birthday when he helped pull from the river a set of legs with about a foot of backbone sticking up. The legs were still clad in jeans and black tennis shoes with white soles, and there was a belt buckle with the initial ‘‘M.’’

Rogan testified that he said to his brother: ‘‘’You reckon that might be Michael Schwerner?’’’ At the time, federal authorities were conducting a massive manhunt for Schwerner and two other civil-rights workers who disappeared from Neshoba County, Miss., on June 21, 1964.

Rogan testified that the legs were double-wrapped with bailing twine.

‘‘No one goes swimming with bailing twine around their legs,’’ he said.

Roland Mitchell was chief deputy sheriff in Madison Parish, La., in July 1964 and served as sheriff from 1968-88. He testified that when the first partial body was found it had a key in the jeans pocket; prosecutors say the key was from Moore’s dormitory room at what was then called Alcorn A&M College, a historically black school in south Mississippi.