Six months after Portland police announced they'd arrested a suspected serial killer who strangled four prostitutes in the 1980s, the man's defense attorney is arguing that police have only flimsy circumstantial evidence to tie him to three of the murders.

Homer L. Jackson III, now 56, did confess to one - the September 1983 death of 14-year-old Angela Anderson, attorney Conor Huseby concedes.

But a cold case detective falsely claimed in his police report that Jackson admitted involvement in all four killings and then shared those purported confessions with a grand jury to get the indictments, Huseby contends in court papers.

The other cases are weak at best and even the Anderson case is questionable, he argues in a lengthy motion seeking to dismiss the indictments.

Police announced last October that they had charged Jackson in the death of two teenagers and two women in their 20s: Essie Jackson, 23, in March 1983, Tonja Harry, 19, in July 1983, Anderson in September 1983 and Latanga Watts, 29, in March 1987. Homer Jackson and Essie Jackson aren't related.

Police spokesman Sgt. Pete Simpson said then that police had linked Jackson to the killings "through forensic evidence and or other investigative information.''

Similarities in the crimes also helped investigators link the deaths, prosecutors and police said. Each of the victims was African American, died of asphyxiation by strangulation or a ligature, was sexually assaulted and found with their shirts pushed up over their chests and walked the old Union Avenue, now Martin Luther King Jr. Boulevard, as prostitutes, they said.

"To show that one person is responsible for this much tragedy is very satisfying," Detective Jim Lawrence, who led the investigation for the cold case team, said at the news conference last fall.

But Jackson "never once admitted 'to his participation in the deaths of Latagna Watts, Tonja Harry and Essie Jackson' as Detective Lawrence falsely wrote in his police report,'' Huseby said in his motion filed in Multnomah County Circuit Court.

Huseby has reviewed the police evidence and Jackson's hours-long, video-recorded interview with detectives, and said police have no evidence tying his client to Essie Jackson's case and little linking him to the others.

In cases where Jackson's DNA was detected, police also found multiple other male DNA profiles in more incriminating locations at some of the scenes, Huseby said.

"Given the lack of evidence tying Mr. Jackson to the Watts, Jackson and Harry murders, it is difficult to comprehend how Mr. Jackson was indicted for those three murders unless Detective Lawrence told the grand jury he had admitted to killing those three women,'' Huseby said in the court papers.

Multnomah County prosecutors stand by the indictments, contending Homer Jackson confessed to Anderson's killing, "made inculpatory statements and admissions" when questioned about Essie Jackson's death and that his DNA was found at three of the four crime scenes, according to their legal brief filed in response.

They also said they intend to show three other women survived alleged strangulation and sexual assault attacks by Jackson in 1981, 1983 and 1988, although none of those cases were ever prosecuted.

"We stand by the legality of the indictments and the police procedures," Multnomah County Chief Deputy District Attorney Kirsten Snowden said Friday.

She also submitted to the court an affidavit, writing, "I was present for the grand jury testimony of Portland Police Bureau Detective James Lawrence, and that I am not aware of any misstatements made by him to the grand jury nor am I aware of any perjured testimony to the grand jury.''

Shortly after Jackson's arrest, Snowden said detectives found new clues after sending untested evidence from the crime scenes to the state crime lab. Newer technology played a role, she said, allowing forensic examiners to get a DNA profile from smaller samples of evidence than in the past.

Huseby lays out his case by describing the evidence from each killing and dissecting his client's statements during the police interview.

He noted that police reports over the years identified other potential suspects in the killings and that police didn't interview some of the people who offered tips. He suggested that police at the time of the deaths didn't investigate crimes involving African American victims as thoroughly as other crimes.

Here's a description of each case and the evidence based on police reports, crime lab reports and the bureau's investigative files cited by both Huseby and prosecutors in their court filings.

-- Essie Jackson's badly decomposed body was found March 23, 1983, at Overlook Park in North Portland. According to crime scene investigators, it appeared someone had dropped her body over the fence and she tumbled about 25 feet down a steep embankment into thick vegetation. An autopsy found she died of asphyxiation by strangulation.

Homer Jackson's name never appeared in the initial investigative file on her death, Huseby said. There's no evidence that he ever met her and no witness ever connected him to the case. There's no physical evidence linking him to the death, Huseby's motion states.

Instead, Huseby said, police found two 6-inch-long Caucasian hairs on Essie Jackson's body; Homer Jackson is African American. Other findings in the police file, Huseby said, showed no DNA from Homer Jackson in scrapings of her fingernails. DNA testing of blood found on her denim pants belonged to an unidentified male, not Jackson, police reports indicate, according to Huseby. Her pimp at the time also waited four days before telling Essie Jackson's mother that her daughter was missing, Huseby said.

"Mr. Jackson, during his interrogation with police, never admitted to even knowing Essie Jackson, let alone participating in any way in her death,'' Huseby said.

Prosecutors, though, said Homer Jackson "admitted to remembering the Overlook Park homicide.'' They pointed to statements he made about not remembering specific details of her death after viewing crime scene photos.

The prosecutors quote Jackson as saying, "I don't know if I rolled her down, threw her down, or whatever ... that's something I don't know.''

When Lawrence asked Jackson if he remembered anything about the homicide, he said, "No, cause I never saw her face,'' the prosecutors' brief said. They note Jackson made the statements after police read him his Miranda warnings.

-- Tonja Harry's body was found July 9, 1983, partially submerged face down in the slough that bordered West Delta Park. She appeared to have died of drowning with possible drug toxicity involved. She had a ligature mark around her neck but no other injuries to her neck. She had lacerations on the back of her head and fresh needle marks on her arms, according to police reports.

The state crime lab analyzed an elastic burgundy belt found broken into three pieces at the crime scene that police suspect was used in a failed attempt to strangle Harry.

Police allege that Homer Jackson's DNA is on the belt, but their conclusion is faulty because DNA from at least three other people also is on the belt, Huseby said.

"In fact, the crime lab was unable to match Mr. Jackson to the belt. Instead, they were simply 'unable to exclude' Mr. Jackson as a contributor to the belt,'' the defense lawyer wrote.

DNA discovered on other items at the crime scene didn't belong to Jackson, including DNA from cigarettes and semen-soaked paper towels, Huseby said. The DNA from the towels and a hair seized from Harry's clothes matched to the same unidentified man, according to the defense motion.

Prosecutors reiterated that the crime lab's analysis determined Jackson couldn't be excluded as a contributor of the DNA profile found on the belt's surface. They also noted that the lab found that the frequency that a random person would have a DNA profile that is also consistent with the partial DNA profile found on the belt is one in every 1.32 million African Americans. In their written response, they don't mention any DNA obtained from other evidence at the scene.

-- Latanga Watts's body was found March 18, 1987, on grass near a sidewalk by the intersection of North Concord Avenue and Going Street. She'd been strangled. A scarf was around her head. A plastic bag or sheet covered her upper torso, suggesting she may have been dragged from the street to where she was discovered.

Homer Jackson's DNA was found under Watts' left-hand fingernails, according to police.

But Huseby noted that the crime lab discovered DNA at the scene from other men. The lab found DNA from at least five males on the scarf, but couldn't develop enough DNA for a full profile. DNA from at least three separate males also was found under Watts' right-hand fingernails, though there wasn't enough to identify a profile. Fingerprints from the plastic bag didn't belong to his client nor did DNA from numerous swabs of saliva found on the sidewalk and ground near her body, Huseby said.

According to prosecutors, the DNA from Watts' left-hand fingernail scrapings matched the DNA found on a cigarette butt left at the homicide scene of Angela Anderson and both are that of Jackson. They don't mention the other DNA evidence found at the scene.

-- Angela Anderson's body was found in a vacant house at 416 N.E. Going St. on Sept. 22, 1983. Her wrists were cut superficially; she had a cord tied around her neck. She died of strangulation, an autopsy found.

Homer Jackson's fingerprint was found on a crawl space door in the room where Anderson's body was discovered, police said. A cigarette butt in the room also was matched to Jackson through DNA, according to court reports.

But additional fingerprints and DNA from the scene came from others, including an unidentified male's DNA on the rope tied around Anderson's neck and another male's fingerprint on a window frame in the room, Huseby said. Jackson's DNA wasn't on the rope, he said.

Given that the murder weapon was a rope cord from a window frame, that fingerprint is significant, Huseby said in his motion.

At one point in his police interview, Jackson incorrectly guessed that Anderson had been stabbed and that he had killed her with "maybe a knife,'' Huseby said. All the while, detectives showed Jackson detailed photos of the crime scene, explaining what certain evidence was when he guessed incorrectly, the lawyer said.

According to prosecutors, Jackson recalled meeting Anderson at Irvington Park, they talked about a prostitution deal and she recommended they go to the Going Street house.

Jackson remembered Anderson's killing because she was young, and he told detectives that he still dreams about her, prosecutors said.

"I know I did kill her. I think I strangled her. I think that's what I did,'' Jackson told police, according to the District Attorney's Office.

Related: Rare glimpse of police interrogation of accused serial killer offered in court papers

-- Maxine Bernstein

mbernstein@oregonian.com

503-221-8212

@maxoregonian