The temperature pushed 90 degrees and the sun beat down on the sopping brow of Joe Madison yesterday at the Prince George's County Courthouse in Upper Marlboro. He wore a black shirt and black pants, which sucked in the heat like asphalt.

The WOL afternoon talk-show host downed a bottle of orange juice and listened to the chants of the 60-some people gathered around him:

"No justice, no peace! No racist police!"

The Rev. Imagene Stewart, founder of a shelter for battered women in Washington, sang a verse of "Keep Your Eyes on the Prize." Then she mopped her forehead, shielded by a hat, and asked the Lord: "Please give Joe Madison the strength to keep this up, day after day."

Yesterday marked the 108th day of Madison's most recent hunger strike, which aims to persuade Prince George's County prosecutors to reopen a 1993 case in which the police shot a handcuffed motorist to death. Since Feb. 15, Madison has eschewed solid food, subsisting on juices, vitamins, an occasional bowl of soup and concoctions prepared by Dick Gregory, the former comedian and practiced hunger-striker. ("He's got me drinking something with grass in it now," he grumbled.)

Madison, 49, is a longtime activist and radio host. And he is becoming something of a practiced hunger-striker himself. He became executive director of the Detroit NAACP at age 24; he came to Washington in 1989 to host a show at the now-defunct WRC. One year ago, he moved to WOL-AM, where he uses his daily 4-to-7 p.m. program to address civil rights issues, often by immersing himself in them.

Madison's tactic of choice--three times in the past 13 years--is the hunger strike.

"People ask me, 'Does this hunger strike have an effect?' " Madison told the crowd yesterday. "Oh, yeah." He stuck his left hand in the front of his shirt and pulled it out several inches. "This used to fit." The crowd laughed.

Slimming down is a side effect; humor is a necessary crutch. But Madison is serious about trying to get State's Attorney Jack Johnson to reopen the investigation into the shooting death of 24-year-old Forestville resident Archie Elliott III by two police officers, one black, one white, one from the county, the other from District Heights. Elliott, who was pulled over three minutes from his house, failed several sobriety tests and was handcuffed and placed in the front seat of a police cruiser. Police said they thought Elliott pointed a gun at them, and they fired 14 times into the police car. A county grand jury investigated the case and decided not to indict either officer.

That hasn't stopped the dead man's mother, Dorothy Elliott, a Prince George's high school teacher, who has kept after Johnson. He has said he cannot reopen the case without additional evidence, saying in a statement that an appellate court, ruling in a civil suit filed by the Elliott family against the officers, "determined that the officers' actions were reasonable."

But Dorothy Elliott and those who have taken up her cause are perplexed by the case's unanswered questions: How could a search of her son--who was wearing shorts and no shirt--have failed to turn up a handgun? And how could he have pointed a gun while his hands were cuffed behind his back?

Madison has had Dorothy Elliott on his show several times. Madison organizes the Wednesday protests in Upper Marlboro, now in their sixth week. And Madison uses his frequent-flier miles to spread news of the case to other black communities around the country. Elliott is thankful for Madison's work, but she worries about his health during the hunger strike.

"I get concerned any time I don't hear him on the radio on his scheduled time," she said. Yesterday, she marched in a T-shirt bearing the likeness of her son on the back. On the front was a picture of handcuffs. "Unless I know he is scheduled to go someplace else and speak, I wonder where Joe is and is he all right."

Madison's first hunger strike came in 1986, while he was protesting South African apartheid. It lasted 60 days. The second, to protest the CIA's alleged involvement in cocaine smuggling, lasted nine months of 1997.

"Fasting has an ability to bring the truth out," Madison said. But how much effect do his fasts have? And how many hunger strikes can he embark upon without losing his credibility?

The answers are unclear.

Madison began his second hunger strike in response to a 1996 series called "Dark Alliance" in the San Jose Mercury News, alleging a CIA-cocaine link. Though that series was largely discredited, Madison finds vindication in a 1998 CIA report that says the agency ignored evidence that the Nicaraguan contras were planning on selling drugs in the U.S. to finance their insurgency.

Madison's current hunger strike focuses on the Elliott case but has racially motivated police brutality as its larger target. He ticks off the cases: Amadou Diallo, the immigrant killed by New York police in February. Abner Louima, brutalized by a New York police officer in 1997. Tyisha Miller, 19, killed by Riverside, Calif., police in December. And the killing of a homeless woman, Margaret Mitchell, by Los Angeles police two weeks ago. Madison believes that blacks are increasingly being targeted by police. This is worse than a return to the bad old days, Madison says--today's police brutality borders on systematic, state-sanctioned violence. Which is why this hunger strike, and why now.

"We're where the past meets the present meets the future," Madison says. "There are points in history where those three axes cross, and that's where we are."

Madison says gravely--and with a touch of drama--that he has no exit strategy for this hunger strike. And, though no one will say it publicly, there are those who wonder how he will declare a victory in a case that the prosecutor says he has no legal basis for reopening.

What does Madison do now?

He pushes on, surrounded by family.

Recently, while grilling catfish for them, Madison playfully asked his 19-year-old son if he could have just a nibble.

"Why don't you call Mrs. Elliott and ask her?" his son retorted. His youngest daughter keeps it lighter--she makes him take her to the McDonald's drive-through and waves french fries under his nose.

"I hope one day there will be no issues and he can relax," said Madison's wife, Sharon, who was at the rally. "But for now, he's going to keep busy."

Yesterday in Upper Marlboro, Madison kept busy, leading the protesters as they marched around the courthouse, invoking Joshua's circling of the walls of Jericho. One man blew a ram's horn. And even though Madison says he will continue fasting and marching, perhaps there was some small part of him--laboring under the blazing sun, stomach churning--that wondered if he was walking in circles.

CAPTION: WOL host Madison, with protester Cornelia Minor, still hopes to persuade officials to reopen the case of a motorist killed by police.

CAPTION: Madison, far right, listens as Charles Holley recounts being pulled over by police on Suitland Avenue.