Dressed in gold pants, a brown shirt open to the waist and black cloth shoes, convicted murderer Charlie Brooks Jr. lay strapped to a stretcher early this morning as two dozen witnesses entered the small death chamber in Huntsville, Tex.

Asked if he had any last words, Brooks looked over at Vanessa Sapp, 27, with whom he earlier had shared "vows," but had not officially married, and said, finally, "Be strong."

"It was as if he was waiting for a change, waiting for something to hit him," said Dick Reavis, one of four press witnesses in the room. "I don't think he felt it." Brooks took "a long, deep yawn. By the time he had finished the yawn, he was gone," Reavis said.

Brooks' execution was the first in the nation by injection and the sixth since the Supreme Court reinstituted the death penalty in 1976. It immediately touched off a controversy over judicial handling of the case.

The decision of the Fifth U.S. Circuit Court of Appeals to deny a stay of execution without holding a hearing on the merits of Brooks' case and the subsequent 6-to-3 Supreme Court refusal to block the execution came under sharp criticism.

"Until this started I didn't think a civilized person would argue that a condemned man didn't have the right to a meaningful, fully briefed appeal," said John Duncan, Texas director of the American Civil Liberties Union. "If you go to the Fifth Circuit, you will find a live appeal and a dead plaintiff."

Some legal experts said the Supreme Court's handling of the case suggests that it is willing to tolerate a telescoping of the appeals process, something that opponents of the death penalty fear could open the floodgates to wave of executions. Others, however, say the Brooks case was unique, raising few constitutional questions that would prompt an appeals court to rehear the case.

"I do not think it has opened the floodgates," said Henry Schwarzschild, director of the ACLU's capital punishment project. "The legal remedies for people at the head of the death row pipeline will begin to be exhaused in another year or year and a half. At that time, the flood-gates will open."

As of mid-October there were 1,102 prisoners sentenced to death in the United States, according to a monthly census by the NAACP Legal Defense Fund. Of that group, 51 percent were black, 42 percent white, and the rest other minorities. There were 13 women on death row.

These prisoners were concentrated in southern states, with 188 in Florida and 120 in Georgia. The NAACP Legal Defense Fund count showed 153 in Texas, but the Texas Department of Corrections said today it counts 171 prisoners on death row. Many of these face execution by injection, a new form of execution legal in five states and used for the first time today.

Strapped to a hospital gurney, or stretcher, Brooks was connected to two intravenous tubes about 12:30 a.m. today. At 1:09 a.m. Washington time, after a final appeal to the Fifth Circuit had been rejected and Texas Gov. William P. Clements Jr. refused to grant a reprieve, a lethal dosage of three drugs was fed into one of the tubes and at 1:16 a.m., Brooks was pronounced dead.

Witnesses said death appeared to be painless, although Brooks yawned, gasped, wheezed and his stomach moved up and down as the drugs were administered.

Brooks, 40, was convicted, along with his boyhood friend, Woody Loudres, of a kidnap-murder of a Fort Worth used car lot mechanic.

The two men were sentenced to death in separate trials, but Loudres conviction was overturned on appeal because of errors in jury selection.

Last month Loudres pleaded guilty to the crime and was given a 40-year sentence. He will be eligible for parole in about six years.

The crime occurred Dec. 14, 1976. Loudres was high on heroin and Brooks had been drinking. They, along with a prostitute, were planning to go shoplifting when their car stalled. Brooks went to a used car lot, where he said he wanted to "test drive" an automobile. A young mechanic, David Gregory, 26, was sent along.

Brooks linked up with Loudres and they drove to a motel, where they tied up Gregory in one of the rooms. Brooks was seen with a gun and threatened the manager's wife.

A few minutes later, a shot was fired, and police later found Gregory dead with a bullet to the head. Neither man admitted pulling the trigger, and prosecutors never proved which of the two was the triggerman.

Jack V. Strickland, the prosecutor in the case, intervened in Brooks' behalf, arguing that the state of Texas might be executing a man who had not actually committed the murder.

As the hour of the execution drew near this morning, a large crowd gathered in the clear, chill night outside the Walls Unit of the Texas Department of Corrections in Huntsville, about 70 miles north of Houston. The group included representatives of Amnesty International and other organizations opposed to the death penalty, as well as a number of students from nearby Sam Houston State University who supported the execution and held up signs that said, "Kill 'em in vein," and "Justice Finally Prevails. Hi Mom."

Brooks, who had converted to the Islamic faith in prison and had prepared himself to die, had eaten his last meal of steak and french fries about five hours earlier, having previously bid farewell to his niece and an Islamic clergyman.

Outside the death house sat Brooks' ex-wife, Joyce Brooks, and her two sons, Derrick, 21, and Adrian, 20. None had been allowed in to see Brooks. Reporters said the boys were weeping.