Refusing by a single vote to institute capital punishment for all premediated murders, the Virginia General Assembly passed legislation today to make the state's death penalty conform to recent U.S. Supreme Court decisions.

The legislation enacts new procedures required by the Supreme Court to punish by death murders committed in the course of robbery, rape, kidnapping or extortion demand, murders by prison inmates. The Senate still must decide whether also to make the kill of policemen a capital crime.

After 2 1/2 hours of debate, the House of Delegates voted 49 to 48 to defeat a proposal that would have made anyone convicted a first-degree murder subject to the death penalty.

Today's action means that Virginia is likely to be the first jurisdiction in the Washington area to adopt a new capital punishment procedure designed to meet the court's latest standards. Gov. Mills E. Godwin asked for such legislation.

The Maryland Senate hs approved legislation similiar to the bill passed in Virginia today, but the Maryland bill, which would make murder under eight conditions a capital crime, still needs House approval. The District of Columbia does not have a death penaly measure that conforms to the court's ruling and has not since 1972, an official in the U.S. Attorney's Office said today. There is no move under way in the District to enact such a measure, the official said.

There were at least six votes today in the House on death penalty matters before the broad death penalty was defeated and the House approved an amendment to broaden the number of death penalty crimes to include the killing of an on-duty policeman.

Rejection of the broad Virginia death penalty came on a 49-to-48 vote after Del. Donald Dunford (D-Tazewell) switched his vote to favor removing the provision, but then called for reconsideration of the measure.

That move failed by a tie 48-to-48 vote and the House then proceeded 74 to 24 to add murdering an on-duty police officer to the five forms of murder currently punishable by death, a step that supporters of the broad death penalty had just argued was foolish.

"A killing is a killing is a killing," said Del. John L. Melnick (D-Arlington), a Democratic candidate for attorney general, claiming that the state should stop its "Christmas tree list" approach of listing specific forms of murder punishable by death.

Other delegates in the 100-member House disagreed sharply and argued that the penalty provision was so broad that it was probably unconstitutional and might bright the entire death penalty down in a court test. Although the House had almost annually argued death penalty bills, never in recent years had a bill so broad reached the floor.

Although today's debate included many points raised previously, it also had new elements:

Laughter: The House broke into laughter as Del. Ray L Garland (R-Roanoke), once a U.S. Senate candidate, told them he found the recent execution of convicted Utah murder Gary Gilmore "exalting." Added Garland: "What's so bad about death really? We all face it."

Dismay: Some House members quietly moaned as Del. Eva F. Scott (I-Dinwiddie) told the House that some innocent people might be mistakenly executed under the bill but, "I don't believe it's going to happen very often."

An appeal to lawyers: Former prosecutor Del. Frank M. Slayton (D-Hanifax) who once won a death penalty in a murder case, said the lawyers in the House had a special obligation to reject the broad provisions because the bill probably could not be successfully defended on appeal. "In this realm we have a responsibility we cannot avoid, a duty we cannot shirk," he said.

In the end, no speeches would win the day, agreed both Del. Calvin F. Fowler (D-Danville), chief sponsor of the measure, and Del. Theodore V. Morrison (D-Newport News), an opponent, "I don't believe there is any logic to it," Morrison said. How a legislator votes depends "on a feeling you have in the pit of your stomach," Morrison said.

"The question boils down to this: If we're going to have a death penalty, let's have one that makes sense," Fowler argued. He claimed the state's current law of singling out the conditions of murder punishable by death was "silly."

Fowler argued that any murder that is "willful, deliberate and premediatated" - a first-degree murder - should be subject to a possible death penalty or life imprisonment.

Senate acceptance of the House-passed bill conforming Virginia's rulings came on a 36-to-2 vote. Sens. Joseph V. Gartlan (D-Fairfax) and L. Douglas Wilder (D-Richmonds), veteran death penalty opponents, voted against it.

Gartlan offfered an amendment that would have requried juries or judges to find that a convicted murderer could not in the future "conform his conduct to the law." Gartlan argued that his amendment would insure against execution of insane persons. It was rejected by voices vote.

Wilder is the Senate's only black member and has often argued that imposition of the death penalty has discriminated against blacks. Today he contended that the proposed procedures should be more explicit in requiring written opinions in death penalty reviews by the state Supreme Court. He also said that the standards in the bill for deciding which murders are heinous are too vague.

The bill passed today repeals the mandatory imposition of death for conviction of one of the five specified capital murders. It required judge or jury to impose death only after a second proceeding to determine the future threat posed by the convicted killer.

The bill also permits the jury or judge to impose the death penalty on a finding in the second proceeding that the murder was especially heinous. As an alternative to the death sentence, the bill provides for life imprisonment.

Northern Virginians split over the move by Del. Warren G. Stambaugh (D-Arlingtn), a death penalty foe, to strip the broad provision from a Senate bill. Supporting Stambaugh were Dels. Floyd C. Bagley (D-Prince William), Earl E. Bell (D-Loudoun), James H. Dillard (R-Fairfax), Wyatt B. Durrette (R-Fairfax), Richard Hobson (D-Alexandria), Ira M. Lechner (D-Arlington), and Dorothy S. McDiarmid, Thomas J. Rothrock, Richard L. Saslaw, Raymond E. Vickery, Carrington Williams, all Fairfax Democrats.