Several of the young people who are on trial for the murder of Catherine L. Fuller were in a park near where she died Oct. 1, 1984 getting high and talking and singing about needing money, a man who said he knew several of those accused testified yesterday in D.C. Superior Court.

Moments later, said Melvin Montgomery, 22, somebody said "they're going to get that one" and pointed to a corner where a woman was standing. The group dispersed, he said, and started crossing the street.

Montgomery, who said his daughter is the godchild of one of the people charged with beating Fuller to death during a robbery attempt, was the first prosecution witness to place some of the defendants near the alley where Fuller was killed. Montgomery yesterday said he saw at least five of the young people in the park the day Fuller was killed.

Montgomery's testimony on the third day of the trial supported a key prosecution claim that a large group of young people, who regularly gathered in the park at Eighth and H Streets NE, spotted Fuller as she walked by and decided to follow and rob her. Prosecutors say that the 48-year-old Fuller, who weighed 99 pounds, was beaten in an alley behind the 800 block of 9th Street and dragged into a nearby garage where a foot-long pipe was shoved into her rectum because she resisted when the group of young people tried to rob her of a coin purse.

Montgomery's testimony also provided one of the trial's first looks into the neighborhood around the blighted H Street corridor. Montgomery described an area beset by poverty and unemployment, where the first of each month is spent cashing welfare checks and where young people have little to do but pass time in a park. Many of those accused of killing Fuller had dropped out of high school and did not have jobs to support the children they fathered as young men.

Montgomery, whose testimony was so nearly inaudible at times that at one point Judge Robert M. Scott excused the jury and admonished him to speak up, described Oct. 1, 1984, as a day like most other days for him: waking up late, picking his daughter up from school, smoking "some reefers" and going back and forth to the park.

Nearly every time he passed the park, Montgomery said, he saw the same group of people, including four of the defendants.

After about his fifth trip to the park that day, sometime in the afternoon, Montgomery said he saw "Tim-Tim" Timothy Catlett, 20, of 821 Ninth St. NE standing with a large group and singing a popular Chuck Brown song, whose lyrics he said went, "We need some money, we need some money, gotta have some money." Others in the group were talking about the song and getting "high . . . drinking and smoking."

While Catlett was singing, Montgomery said he heard someone say "they're going to get that one." He said he turned and saw Russell Overton, 26, of 821 Ninth St. NE, pointing to a corner where a woman was standing. Montgomery identified Overton as his child's godfather.

"Then they started to leave . . . . I saw them going into the street," said Montgomery.

When Assistant U.S. Attorney Jerry S. Goren asked who, Montgomery identified the four as Overton; Catlett; Levy Rouse, 20, of 4427 Hayes St. NE, and Charles Turner, 21, of 1018 11th St. NE.

"Other people left too. They were going into the street, too," continued Montgomery. "But when I looked back they were gone."

Soon after, Montgomery said, he too left the park. When he returned later, Montgomery said he saw 17-year-old Clifton Yarborough of 911 Ninth St. NE, another of the defendants, trying to break up a fight near the corner of the park.

Questioned by some of the defense lawyers, Montgomery said he regularly saw the same group of people in the park -- including four of those he named yesterday -- and that they often sang songs, including the Chuck Brown song about money. Montgomery also said that when he heard someone say, "Let's get that one" he did not know the substance of the group's conversation, nor did he know if Russell Overton was pointing to a woman on the street corner, or just across the street.

Montgomery also told defense lawyers that he only cooperated with police investigators after he was told by a police officer that "if I didn't remember something right they'll take me over" to jail "for five days until I remember."

The other defendants on trial are: Alphonso Harris, 23, of 907 Eighth St. NE; Felicia Ruffin, 17, of 27 15th St. NE; Kelvin D. Smith, 20, of 1007 Fourth St. NE; Christopher Turner, 19, of 1018 11th St. NE, and Steven Webb, 20, of 1335 Emerald St. NE.