More than 200 persons jammed into the Prince George's County Courthouse yesterday as Judge Vincent J. Femia denounced what he characterized as a barrage of attempts to influence the court in the case of 15-year-old Terrence G. Johnson, accused of killing two county policemen last June.

Femia, hearing evidence to determine if Johnson should be tired as a juvenile or an adult, said the influence attempts had come "almost exclusively of them suggested, he said, that because the defendant is black his case should be handled in some "different" fashion - "something along the lines of black justice."

Johnson, whose case has become a cause celebre in the black community here, is accused of shooting officers Albert M. Claggett IV and James Brian Swart in the Hyattsville police station as they tried to book him on charges of attempting to break into a laundromat. Both officers were white.

"To suggest in this day and age," said Femia of the "minority tone" of the letters he received," that justice should be determined on the basis of race is gross insult to justice and a personal affront."

He said that the majority of the letters he received "showed a total and complete ignorance of judicial sense. You people don't know what we do here," he told the overflow crowd.

"Whoever stared this (letter-writing) campaign is surely a false prophet, Femia said, "because he has made fools of all the people who would sign their names to these letters. Where would we be if justice were decided by plebiscite? We would be sowing the seeds of our own self destruction."

Outlining the five criteria he will use to decided if Johnson should be tried as a juvenile instead of an adult Femia said, "Those are the rules, that's all."

They are: age, mental and physical condition, amenability to treatment in the juvenile system, the nature of the offense and the safety of the public.

"All the walking, talking, foot-stomping and demonstrating won't do any good with this member of the bench. We're just going to play it by the book."

And with that, he began the hearing that will determine whether Johnson, if convicted, will be free of the court's jurisdiction at the age of 21, or if he will face life imprisonment, one of the issues at stake in a juvenile waiver hearing.

The hearing continued into the evening yesterday as defense attorneys produced witnessess to testify to Johnson's good character, and the prosecution attempted to portray him quite differently.

Johnson sat quietly in a tense courtroom, which could be entered only by passing through a metal detector, and said during a recess that he was "scared of what could happen to me."

Johnson, who was released on $100,000 bond early Tuesday morning, stared straight ahead as Femia heard preliminary motions from the youth's three lawyers, R. Kenneth Mundy, Joseph L. Gibson, and Alan Lenshek, and from State's Attorney Arthur A. Marshall Jr., who is prosecuting his first case in almost three years.

Femia disamissed a motion by Johnson's former teachers as character wit from the hearing because Femia has been an outspoken advocate of stricker juvenile justice.

His lawyers called three of Johnson's former teachers character witnesses and then rested their case that he be tried as a juvenile.

All three testified that Johnson had been cooperative and well-behaved for the most part in their classes, One of them, Robert C. Pell, the youth's wrestling coach, called him "a class leader."

Marshall produced shcool records showing that Johnson received an "A" from Pell but had been absent 36 times.

IN an interview during a recess, Johnson said, "It feels good to be out of jail but I know it's not over yet. I'm feeling pretty good but it bothers me to sit here and hear a lot of things that aren't true.

"Being out isn't really helping me that much except that I'm less tense. I keep reminding myself it isn't over with.

"I love being back with my family though," he added "I plan to work, get a job I hope and get a tutor to keep up with my studies."

Johnson said the support he had been receiving, "takes a lot of fear out of me. It's good to know the whole world isn't against me because sometimes in the detention center, I felt that way.

"Im still worried though, worried about my jury I just want to get some people who will be fair and listen to what I have to say, not just what they say I did."

Asked how he felt about the whole thing, Johnson said, "I'm scared, scared of what could happen to me, scared of the idea of going back to jail, especially from what I picked up while I was there. The idea of going back scares me."