The judge was ready. The jury was set. The defendant and his attorney were waiting at the defense table. Everyone was ready to proceed yesterday in the trial of 32-year-old Brevard Browner, who faces charges of armed robbery and burglary while armed.

Everybody, that is, except the prosecutor, who couldn't find her two main witnesses. Before the day was over the jury had been dismissed and Browner was back in jail. Police, meanwhile, had gone out in search of the two witnesses, who they say have disappeared.

A police detective told D.C. Superior Court Judge Joseph M. F. Ryan in court yesterday that based on information supplied by an informant, Browner is suspected of paying the witnesses $500 to stay away from the trial and booking them into a Northeast Washington motel room.

Ryan yesterday ordered Browner held in lieu of $100,000 bond and ordered a new trial held in May.

Police were continuing their efforts to find the two witnesses, who authorities believe were staying at one time at the Capitol City Inn at 1850 New York Ave. NE. A check at the motel Monday revealed that Browner--who until yesterday had been free on bond pending his trial--had booked a room there Friday, a police detective testified in court yesterday. But by midday Monday, whoever had been staying there was gone.

Browner's attorney, Sol Z. Rosen, asked in court that the case be dismissed for lack of prosecution.

"The allegations are very serious and I'm very sorry the case had to break down this way," Rosen said in an interview later. "My client denies any involvement" in the alleged obstruction of justice.

The witnesses in question, both women, had been codefendants with Browner on charges stemming from a 1981 burglary of a Southwest Washington home. In that incident, according to court records, two masked men and a woman entered the house and forced the occupant to lie on the floor while they stole a television set, a camera and about $50 in cash.

According to a police affidavit in the case, the suspects fled and were pursued by police. One man got out of the getaway car and escaped on foot. Browner was arrested, as well as two women, Mabel D. Galloway, of 4724 Benning Rd. SE, and Darlene Harvey, of 2101 H St. NE.

All three were charged in an indictment on counts of armed robbery and burglary while armed. Harvey was charged with being an accessory after the fact, for allegedly helping the suspects to flee.

Originally all three defendants were scheduled to be tried in April of 1982. That trial date was continued and in October Harvey pleaded guilty to two counts of being an accessory after the fact. In February, Galloway pleaded guilty to two counts of robbery.

In an arrangement with prosecutors, both women were given suspended sentences and placed on two years' probation in exchange for their agreement to testify against Browner, who faces life in prison on the charges.

Prosecutor Kathleen Voelker, noting that Galloway and Harvey had yet to be found, declined to comment after yesterday's court session. Ryan, saying that "the government is being frustrated in presenting its case," ordered Browner sent to D.C. Jail.