More than six months after four persons were found shot to death in a Southeast Washington apartment, a special D.C. police task force has been assigned to rework the case, which some veteran investigators said has been bungled since the morning the bodies were found.

The quadruple slaying constitutes the biggest murder case in the District in more than a decade, but sources familiar with the investigation said it initially was not made a priority and that probers were unable to capitalize on crucial leads that might have led police to the killer -- in particular bloody footprints and a bite mark on one of the female victims.

To add to the continuing difficulties in the police's handling of the case, the U.S. attorney's office has decided that there is not sufficient evidence to certify the police department's request for an arrest warrant for a key suspect. That request was made within the past month.

Prosecutors subsequently offered to take the case before a grand jury, but the police department has not asked them to do so, sources said, and the department last week named a special seven-member task force to work on the case.

Deputy Chief Alfonso D. Gibson, head of the D.C. police Criminal Investigations Division, said yesterday that "this case has been actively investigated since the day it occurred" and termed any suggestion of lax police procedures "absolutely false."

Saying that he would not comment on "any substantial evidentiary facts of the case," Gibson denied that the investigation was not treated as a high priority. He refused to address specific questions about the investigation except to say that "apparently you have talked to someone who is not familiar with this case and who is giving you bogus information."

Gibson said he believed that the Post report was designed to "pay back favors to members of the homicide squad" and that the story was being written out of "vindictiveness."

"I think it is inappropriate for the Post to run specific details of this investigation when we have alternate plans for doing things in this case," Gibson said, adding that it could "hamper the investigation drastically." He declined to elaborate.

At the center of the controversy are the killings that occurred early on the morning of Tuesday, April 9, in a second-story garden apartment at 2839 Robinson Place SE, where Juanita Beasley, 22 and Carolann Resper, 26, lived.

Police went to the apartment about 9:30 that morning after Resper failed to show up at D.C. Superior Court, where she was expected to testify against her estranged husband and his brother in an armed robbery trial.

Officers were let into the locked apartment by Carolann Resper's relatives. It was unusually warm, even hot, inside the apartment; the outside temperature during the night had dipped to 36 degrees.

Resper and Beasley were found lying face down on the living room floor with Resper's boyfriend, Reginald Harris, 26, lying between and almost on top of the women -- an arm around each, as if to protect them, according to a police source. All three were dead; each had been shot at least once in the head.

Beasley's boyfriend, Ronnie Best, was found slumped in the doorway of the bedroom.

He had been shot between the eyes, apparently while standing, and in the neck, probably after he fell, a source said.

Blood was everywhere, and it had been tracked about the apartment by the killer, leaving bloody tennis shoe prints. In all, a police source said, 11 shots had been fired, all from the same handgun, a .32 caliber. It was not found.

Photographs of the four bodies and videotapes of the apartment were made before the bodies were taken to the medical examiner's office for autopsies.

Sources said that because of the heat of the apartment, the examinations did not reveal an exact time of death, but that the four probably were killed between 2 a.m. and 4 a.m.

Investigators first focused on Resper's husband, Ronald, as the prime suspect. He was questioned about six hours on the day the bodies were discovered and was given a polygraph test. The results of the test supported his assertion that he was not involved. Witnesses said he was clearly stunned when he was told of the deaths by courtroom officials.

(Ronald Resper was recently convicted by a D.C. Superior Court jury of the armed robbery charge; his brother was acquitted in the same case.)

With the results of the polygraph test blunting their case against Ronald Resper, investigators turned their attention to several other possible suspects. But, sources said, errors made in the early stages of the investigation made it difficult for police later to press a case against any other suspects.

Among the errors they listed were:

Some items later thought to be in the apartment at the time of the killings were not on the inventory list made at the crime scene shortly after the bodies were found. For example, relatives of Juanita Beasley said that she had had $700 in cash on Monday, the day before she died. Police later were not able to determine if the money, possibly in her pocketbook, was in the apartment when the bodies were discovered.

The initial search of the crime scene was incomplete -- for example, at least one of the bullets was not found until the next day.

Until last week, a special team of detectives was not assigned to the case, the largest multiple homicide in the District since Jan. 18, 1973, when seven Hanafi Muslims were killed at the organization's 16th Street NW headquarters.

Some residents of the apartment building, many of whom said they were at home when the killings probably took place, were not questioned extensively when they said they had heard nothing. Police sources said the shots would have been heard outside the second-floor apartment, and a neighbor who lived in another building reported hearing "lots of shots" about 3 or 4 a.m.

Police have been unable to match with a teeth impression a bite mark that was discovered on Carolann Resper's right wrist near the base of her thumb. An impression of one possible suspect's teeth was taken, after police obtained a search warrant, but a dentist who examined the impression said it did not match the mark on Resper.

When officers left the Robinson Place apartment late in the day, it was relocked -- as police had found it -- and festooned with yellow "Crime Scene Do Not Cross" tape. The apartment was not put under surveillance and the locks were not changed, even though police had found the door to the apartment locked and dead-bolted when they arrived searching for Carolann Resper. A male friend of Juanita Beasley later told police that he used Beasley's keys to gain entrance to the apartment after police had left.

The man was told to leave police headquarters, where he was being questioned, at the same time that an investigator was out of the office looking for two women who the man said could verify his whereabouts for the time of the killings.

The same man, when interviewed by police on the day the bodies were found, arrived at police headquarters wearing tennis shoes that were speckled with brownish red spots. Because the man was not, at that time, considered a suspect, no examination of the shoes was made.

Police later determined that the man wore the same size tennis shoes as those that made the bloody prints at the scene of the slayings. Police searched the man's house, but none of three pairs of tennis shoes examined matched the prints at the scene.

Deputy Chief Gibson denied that a proper inventory was not taken and that the apartment was not adequately sealed from intruders on the day that the bodies were found.

About a month ago, the D.C. homicide division sent to the U.S. attorney's office an affidavit seeking an arrest warrant for the man. According to sources familiar with the investigation, the affidavit was reviewed by about eight prosecutors, none of whom believed that the evidence was sufficient to support an arrest or lead to a conviction.

Although some of the prosecutors who reviewed the affidavit thought police have "close" to sufficient evidence, a police source said, "the majority said they wanted no part of it."

"Homicide is notorious for locking suspects up and then abandoning the case," the source said. "Once homicide has closed the books, homicide has finished the case."

The man told police that he had been inside Beasley's Robinson Place apartment between 8 and 10 the night before the four bodies were found, according to police sources. Other persons told police they saw the man inside the apartment building about the same time.

The man told police that he left to pick up his mother at work about 11:30 p.m. and then returned to his apartment about 1 1/2 miles away from the Robinson Place address, and that he was there alone and did not talk with anyone until about 11:30 the next morning.

The man's mother told police that her son had driven her home from work and that she had talked with him by telephone the next morning about 8 a.m.

According to police documents and sources, on Tuesday -- the day the bodies were found -- the man had the receipt for a $75 money order that Beasley had purchased the day before.

The man told police that when he went to the women's apartment on Tuesday night, he removed Beasley's pocketbook and later gave it to her relatives. But according to police sources, the man told Beasley's relatives that she had left the pocketbook in his car on Sunday, April 7.