Revenge appears to have been the motive in three of four killings that police have linked to alleged peeping Tom shooter Ricky Brogsdale, according to the police account of Brogsdale's videotaped statement.

But puzzled police investigators are still trying to piece together the motive for a fourth slaying and an explanation for the pattern of peeping Tom shootings they also tie to Brogsdale. The shootings -- which recently terrorized the Southeast neighborhoods of Congress Heights and Washington Highlands -- are emerging as one of the city's most complicated and perverse crime rampages.

"It is one of the most involved murder cases we've ever had," said a police source. According to police sources, in Brogsdale's long, rambling statement to police, the first slaying he said he committed was to avenge an assault of his mother 11 years ago. The second was revenge for the killing of his sister two years ago, police said. A third one, committed because he thought the victim had "ripped him off" in a past drug deal, may have been a mistake, he said, according to police.

"He wanted revenge," one D.C. police source said of Brogsdale's alleged killings. "He wanted to get back at the people who hurt him and his family in the past."

Police sources describe the 26-year-old Southeast Washington man, who has an extensive arrest record of violent and sexual crimes, as a "cold-hearted, calculating" man who "enjoyed the attention he was getting." However, Brogsdale's attorney, public defender Ellen Kreitzberg, criticizes police for their characterization, and paints him as a "troubled and complicated young man who is a victim of the criminal justice system."

"It's dangerous to oversimplify what is clearly an extremely complex situation," said Kreitzberg.

Brogsdale was arrested and charged with the first-degree murder Oct. 17 of 35-year-old Yvonne Watts, shortly after he allegedly fired a fatal shot through the open window of her parents' apartment on Mississippi Avenue SE. Brogsdale claimed responsibility for the slaying, saying that Watts resembled someone who had stolen his drugs, police said.

When police brought Brogsdale in for questioning in connection with that attack, he launched into a detailed account of two of the other slayings and a string of peeping Tom shootings he said he committed, according to police sources and prosecutors. He also said he witnessed, but did not commit, a fourth killing. Police sources said Brogsdale knew he was being videotaped during the 2 1/2-hour questioning by police.

Defense attorney Kreitzberg has called the circumstances of his statement "highly suspect," and said she has not been allowed to see the police videotape of Brogsdale's statement. Although Brogsdale's account has not been made public, during a court hearing last week, prosecutor June M. Jeffries referred to Brogsdale's videotaped statement and said that in it he said he committed three killings -- including Watts' slaying -- and participated in a fourth. In the videotaped statement, Brogsdale also said he was involved in many other assaults, she said.

The alleged revenge killings began Sept. 5 when Brogsdale was walking along a Southern Avenue overpass, and saw Myers Jackson below, according to Brogsdale's account to police.

Brogsdale told police he recognized Jackson as the man his mother told him had tried to rape her 11 years ago. Brogsdale then shot him, police said. Police have confirmed that Brogsdale's mother reported an attempted rape to police in March 1976, but no charges were filed and police have no evidence that Jackson was involved in any such incident.

The day after killing Jackson, Brogsdale set out to kill Steven Wilson, the man he believed had murdered his sister, police said he told them.

In April two years ago, Sharon Brogsdale, 25, was found lying at the bottom of steps at 1708 W St. SE -- the apartment she was sharing with Wilson, who was her boyfriend. She died a few days later from severe head injuries, and police were never able to determine whether she fell or was killed.

But Brogsdale, who was in Lorton prison, told police that he had heard that Wilson had beaten her to death with a hammer, according to police and prosecutors.

On Sept. 6, Brogsdale allegedly entered through an unlocked door Wilson's apartment at the same W Street address where his sister once lived, and made his way to the bedroom where Wilson and his girlfriend Sadie Turner were in bed, Brogsdale told police. He shot several times, fatally wounding Wilson and injuring Turner, police said.

Police also have linked Brogsdale to a fourth fatal shooting -- the Sept. 18 death of Angela Shaw, a woman he said he had met on a bus. The partially clad body of Shaw, 17, who had been shot several times in the head and strangled, was discovered in a wooded area off the 2300 block of Good Hope Road SE on Sept. 20.

Police believe Shaw was a part-time prostitute who had been staying with friends in the area. Although police have determined that Brogsdale's gun was used in the slaying, Brogsdale told them that he witnessed the murder but was not the person who killed her.

Police said Shaw's friends found a handwritten note slid under their door, reading "I raped and killed your friend, Angela Shaw. You can find her on the bike path behind Marbury Plaza." The handwriting on the note is being analyzed, and police are conducting a voice analysis of a 911 telephone tape in which a man told authorities where to find Shaw's body.

During this same six-week period, a shooting rampage occurred in Brogsdale's Southeast neighborhood, which is roughly bounded by Portland Street and Alabama Avenue SE on the north, South Capitol Street on the west and Southern Avenue on the east and south. An additional shooting occurred in Prince George's County, just over the District line.

It was a wild and perverse rampage, of at least six peeping Tom attacks, in which residents were terrorized by an assailant who stalked the neighborhood and spied on people through open blinds, windows or curtains in ground-floor apartments.

Brogsdale told police he shot the people he watched through the windows. In Brogsdale's case, the two strands of his criminal history -- violence and sexual offenses -- were both displayed in those incidents, police said. He told police that in some cases he shot his victims as he was masturbating.

"He was just a deviant individual, a criminal," D.C. Police Chief Maurice T. Turner Jr. said immediately after Brogsdale's arrest. "He was just hell-bent on what he was doing."

When police drove him to the Southeast neighborhood where the slayings allegedly took place, Brogsdale accurately pointed out some of the locations, police said. To their surprise, he pointed out the location of a shooting of which police were not aware.

A .22-caliber handgun recovered at the scene of his arrest is similar to the weapon used in all the shootings, but ballistics and forensic experts are working overtime to piece together details of the attacks. In fact, detectives are reexamining many other open homicide cases since May when Brogsdale was released on parole from prison where he had been serving time for carrying a pistol without a license.

Kreitzberg has criticized police for providing her with no information in the case and unfairly characterizing Brogsdale to the public.

"He is a troubled and complicated young man who has suffered a childhood beset with difficulties," she said. "He has cried out for help in the past."

Brogsdale referred to his "lost" life and the "bad society" he grew up around in a letter that he wrote to a D.C. Superior Court judge four years ago, asking for a sentence reduction, according to court documents.

In the letter, he made many references to God and said that he was trying to pull his life back together. "When I was home, my job was a big help to my family and I didn't mine {sic} working overtime to make sure they had enough food to last until the first of month," Brogsdale wrote.

If the judge granted him a sentence reduction, he wrote that he would never "look this way ever again, because I know what it feels like to be a free man taking care of a family and abidding {sic} by the law of society. Your honor please! Would you do this to help my kids as well as me, because I'm going straighten up my life to help my kids become better people of society."

About four years after he wrote the letter, Brogsdale was released on parole. He violated parole about a month later when he exposed him.elf to a student outside a University of the District of Columbia classroom.

The D.C. Parole Board did not send him to prison because it decided that, based on his parole record, he was not a threat to the community.

"In my view, the parole board did not act judiciously in this situation," said D.C. Council member Wilhelmina J. Rolark (D-Ward 8). "Mr. Brogsdale had a prior history of indecent exposure for which he was on parole. For that reason alone his case should have come under closer scrutiny."