Guardian Angels seek federal intervention

Failing in efforts to get the New Jersey attorney general to investigate the shooting death of one of their members by a policeman, the Guardian Angels are going to the nation's capital Jan. 8 to ask the federal government to intervene. The self-styled citizens crime prevention group has claimed the shooting was ''a cold-blooded killing'' of one of their members by a Newark policeman.

Guardian Angel Frank Melvin was shot to death on Dec. 29 while on an anticrime patrol with fellow ''angels'' in a Newark, N.J., housing project. Newark police say that Mr. Melvin was mistakenly shot by Officer Milton Medina when another angel allegedly advanced on a policeman after the officers had received a call about a burglary in the project.

But according to Curtis Sliwa, the Guardian Angels' founder and leader, several eyewitnesses to the shooting say Melvin was shot intentionally - and at ground level, rather than from a rooftop. Police have vigrously denied that this was the case.

The incident is the most controversal so far in the little more than three-year existence of the Guardian Angels, which claims to have 33 chapters across the nation with nearly 3,000 members.

And with this new controvery the old question raised by some local law enforcement officials in New York, Newark, and other cities once again surfaces: Are the Guardian Angels ''vigilantes'' who use lawless methods to restrain and arrest wrongdoers, and sometimes interfere with the police, as William McKechnie , president of the New York City Transit Patrolman's Benevolent Association and others claim, or are they merely citizens who do not carry weapons who make legal citizens' arrests, as Mr. Sliwa claims?

While New Jersey State Attorney James Zazzali has rebuffed Angel demands that he appoint a special prosecutor, he says he will ''monitor'' the case to see that justice is done. Meanwhile, Essex County Prosecutor George Schneider is conducting an investigation into the matter.

But neither step was good enough for Sliwa, who claims that the county prosecutor, because of his ties to the ''Newark political machine,'' cannot conduct an impartial probe.

After Zazzali refused to launch his own investigation, Sliwa pledged to take the case to the Justice Department Washington.

The charismatic Sliwa has denied that the anticrime group, which close observers say is having ''growing pains'' and had lost some of its knack to attract as much media attention as it had been getting, was merely trying to get attention by this ''march'' on Washington.

''We're not doing it for publicity,'' he told reporters in Trenton, ''we're not looking to hurt anyone, we are simply begging for justice in a terrible injustice.''