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Diana Robertson

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Diana robertson1 mike riemer

Mike Riemer and Diana Robertson

Real Name: Diana Lee Robertson
Nicknames: No known nicknames
Location: Puyallup, Washington
Date: December 12, 1985

Case[]

Details: Twenty-one-year-old Diana Robertson and her thirty-six-year-old boyfriend, Mike Riemer, lived in Puyallup, Washington, with their two-year-old daughter, Crystal Louise. The couple had known each other since Diana was seventeen. Mike worked as a roofer throughout the year and as a fur trapper during the winter.
On the morning of Thursday, December 12, 1985, the family set out for a day in the mountains near Tacoma, Washington. They drove up into the forest in southern Pierce County, a scenic region often frequented by campers and nature lovers. They planned on finding a Christmas tree, and Mike intended to check his animal traps, which were located along an eighty-mile stretch of the Nisqually River between Interstate 5 and Elbe, Washington.
Later that same afternoon, Crystal was found outside the front entrance of a Kmart department store in Spanaway, Washington, thirty miles north of Elbe. She seemed stunned and silent, and her parents were nowhere to be found. Molly Koch, the store’s assistant manager, announced over the store’s intercom that a lost child had been found. She remembers that Crystal did not cry, which she thought was strange because a child of that age would normally cry if they had been away from their parents for that long.
Molly took Crystal back to the toy department and walked her around the store, hoping that something would be familiar to her. However, nothing helped; Crystal walked through the whole store without saying a word. After being checked at a local hospital, she was sent to a temporary foster home. The next day, Crystal and her parents were reported missing. Two days after that, a nurse from the hospital recognized Crystal from a photograph on a news broadcast about her family’s disappearance.
As her parents had vanished, Crystal was taken in by Diana’s mother, Louise Conrad. As soon as Crystal saw Louise, she put her arms out, said, “Grandma!” and ran to her. Louise has had her ever since.
When Crystal was asked where her parents were, all she could say was, “Mommy is in the trees.” Investigators felt she was “not verbal enough” to provide additional information. Louise says that Crystal’s personality changed after she was found. When someone would ask her about her parents, she would stare blankly and appear “not happy.” Louise believes that Crystal saw something or knew something.
Four months earlier, the forest area near where Mike and Diana disappeared had been the scene of two brutal murders. Initially, police made no connection between the couple’s disappearance and these murders. But soon, a connection would prove inescapable.
The same weekend Mike and Diana disappeared, a massive search was launched. Mike’s best friend, Steve Tew, scoured the countryside on the ground and from the air. He started his search at the spot where Mike would normally start his trap lines and followed the whole line to Elbe. He searched for about two or three hours but did not see anything.
Mike’s father, Lloyd Riemer, a retired state game warden, led several searches of the areas where Mike liked to set up his traps. Other relatives and friends searched along roads near the Nisqually River. They, too, found nothing. Lloyd hired a private investigator who found a witness who said they had seen Mike’s truck in the Kmart store’s parking lot between 4 and 5pm on the day of Mike and Diana’s disappearance. However, no other clues were found.
On February 18, 1986, two months after Mike and Diana disappeared, a man pulled off State Route 7 onto a logging road to take his dog for a walk. The area was located in the forest in Lewis County, Washington, near the Lewis-Pierce County line, three miles south of Elbe and just north of Mineral, Washington. While walking down the logging road, he made a shocking discovery: Diana’s partially decomposed body lying in the snow alongside Mike’s red 1982 Plymouth pickup truck.
Crystal was correct when she said her mother was “in the trees.” Diana was nude from the waist up. She had been stabbed seventeen times, and a tube sock was tied around her neck. Police believed the sock was used to “control” Diana rather than strangle her. They also believed that she had been there since the time of her disappearance. No trace of Mike was discovered, although several inches of snow made the new search difficult.
Mike’s family says that they passed the logging road several times during their search but had never checked it because he normally did not put traps there. When Lloyd was told about Diana’s body and Mike’s truck being found, he figured Mike would probably be found somewhere in that area. But extensive searches with bloodhounds turned up no trace of him. Lloyd says he did not know where to look from there.
Steve also believed that Mike would be found close by. He believed that someone had killed them both. He still believes that Mike is dead somewhere. He says there are questions regarding this case that need to be answered.
Some of these questions concern bloodstains that were found in the front passenger seat of Mike’s truck. According to Detective David Neiser of the Lewis County Sheriff’s Department, some of the blood’s characteristics were lost after it was exposed to the elements for two months. As a result, they were unable to determine the blood type. However, they were able to conclude that the blood was human.
Police found another baffling clue. Displayed prominently in the truck’s cab underneath the windshield was a manila envelope that read, “I Love You Diana.” Louise believes it was Mike’s handwriting based on cards that he gave Diana on different holidays. She claims that his signature on the cards matches the handwriting on the envelope. Despite her beliefs, Detective Neiser says the FBI laboratory was unable to conclusively say that the handwriting on the envelope was Mike’s.
Detective Neiser feels that the envelope is an interesting clue. He wonders why it was put there. Was it put there by Mike as a final “goodbye Diana, I’m sorry” situation? Or was it put there by someone else to throw off the authorities and make them think that?
Some police believe that Diana’s murder and Mike’s disappearance may be related to a double murder that had occurred four months previously and just fifteen miles from where Diana was discovered. These murders occurred in Pierce County, an area where Mike frequently set his traps.
On the evening of August 10, 1985, twenty-seven-year-old Stephen Harkins and his forty-two-year-old girlfriend, Ruth Cooper, attended a friend’s wedding reception and then left to go on a weekend camping trip near Tule Lake in southern Pierce County. On August 14, Stephen was found dead in his sleeping bag at their campsite. He had been shot in the forehead. The couple’s pet dog was found shot to death nearby. Ruth was nowhere to be found.
Two months later, on October 26, hunters walking near the dead end of Eighth Avenue South found Ruth’s body and purse about a mile-and-a-half from where Stephen was found. Her skull was later found about fifty feet away from the rest of her body. She, too, had been shot to death. And around her neck, a tube sock was tied.
In a grisly similarity, Diana had another tube sock around her neck – tied in exactly the same type of knot. Detective Neiser went to Pierce County to look at the sock that was found around Ruth’s neck. He says that when he looked at the sock, “the hair stood up on the back of [his] neck, and [he] shivered a little.” He and the Pierce County evidence technician realized that the socks were identical.
Two theories emerged concerning these multiple killings. One was that an unknown serial killer had taken the lives of both couples and hidden Mike’s body. Secondly, some thought it possible that Mike himself was the serial killer. According to Lloyd, Mike always carried a .22-caliber handgun when he checked his trap lines. Interestingly, Stephen was killed with a .22-caliber weapon.
Mike and Diana had a history of domestic violence, and, according to her friends and family, he had frequently beaten her. At least two domestic disturbance complaints between the couple had been filed with the police. Then, just two months before Diana’s murder, on October 19, 1985, Mike was arrested and cited for domestic assault and malicious damage after he allegedly kicked in a door at her apartment, threw her to the floor, and rubbed her face in the carpet. She was able to free herself and call the police. When they arrived, there were visible red marks on her nose and left eye.
Diana’s sister, Darlene Robertson, says it is not natural for someone to beat up the person they love like that so often. But according to Darlene, when Mike got mad, he would beat Diana up. He took everything out on her. He blamed her for things that he did. If he was seeing someone else, he would turn it around on her, act like she was seeing someone else, and justify it in his own mind.
Shortly after Mike’s arrest, Diana secured a court order forbidding him from seeing her. But as Christmas approached, the couple got back together for what would prove to be the last time. Darlene does not know why Diana let Mike come back. She speculates that Diana might have done it because of Crystal or because he was a sense of security for her. Louise says that Diana loved Mike, which might explain why she let him come back. Detective Neiser says it is very common for the victim to allow the abuser back into their lives.
Though circumstantial evidence exists that could lead to a warrant being issued against Mike for Diana’s murder, there is a legal stumbling block: the police cannot prove if he is alive or dead. Detective Neiser says that if they can prove Mike is dead, it would mean an unidentified third party is going around killing people in the woods.
However, Detective Neiser says that if they can prove that Mike is alive, he immediately becomes a suspect, which “changes the situation dramatically.” Steve says Mike would easily get upset and jealous of Diana if she went out. He says that if someone upset Mike enough, Mike would probably say something to them or confront them. But Steve does not think that Mike would kill someone over it.
At one point, Diana told Louise that Mike had threatened to kill her and boasted that he could get away with it. Louise told Diana to be careful but also noted that he could not get away with something like that. At the time, Louise believed that Mike was just saying things to scare Diana.
Lloyd believes there is convincing evidence that Mike is innocent. He says that Mike would not have voluntarily left his coat in his truck since it was freezing cold and snowing at that time of the year. He says that Mike would then have to walk about two or three miles to get out of the area onto a main road.
Lloyd also says that Mike did not have any money on him when he disappeared. He did not pick up his last paycheck, and nothing was taken from his bank account. On the day of his disappearance, Mike told Lloyd that he wanted to quickly check his traps so he could work that Friday through Sunday. Lloyd believes that the killer got to Mike first.
It should be noted that since he vanished, Mike has not made any effort to contact Crystal or another daughter he has from a previous relationship.
Whether Mike is alive or buried somewhere in the Washington woods, the police want to find him. A few people who knew him thought they might have seen him since Diana’s murder. He was a skilled outdoorsman and may be living off the land. He also worked as a roofer and was an accomplished guitar player.
Years later, Crystal still holds onto memories of her lost parents. Louise has a picture of Diana on her dresser. Whenever Crystal gets something new, she takes it into Louise’s room and shows it to Diana’s picture. Louise says that Crystal misses Diana and has talked about her more since her death. She thinks that Crystal has done well considering what she has gone through.
Though Louise and some police suspect Mike was responsible for Diana’s murder, there is also evidence that suggests he might be a victim. For this reason, this baffling case cannot be solved until Mike or his remains are found.
Suspects: Mike was considered the prime suspect in Diana’s murder. He was also considered a person of interest in Stephen and Ruth’s murders. He was known to be abusive towards Diana and had once threatened to kill her. She had secured a court order forbidding him from seeing her but later allowed him back into her life. Police claim he is the only known person with a motive to kill Diana.
However, Mike’s family and friends believe that he is innocent and that an unknown serial killer may be responsible for the murders. There has been speculation that the case was related to drugs or revenge. However, nothing was found to support this.
A possible suspect in this case is Billy Ray Ballard. In 1989, he was arrested and charged with the murders of Edward Smith and Kimberly LaVine. The couple disappeared on March 9, 1985, while on a weekend getaway in Grant County, Washington. They were later found murdered in separate locations, with Edward having his throat slashed. Ballard was linked to them via a fingerprint found in Edward’s car. He later pleaded guilty to Edward and Kimberly’s murders. However, he was never connected to this case.
Extra Notes:

  • This case first aired on the September 6, 1989 episode.
  • It was excluded from the FilmRise release of the Robert Stack episodes.
  • It was also profiled on The Trail Went Cold and Washed Away podcasts.
  • Some sources state that Diana and Mike were planning to camp in the area; Louise recognized Crystal from a news broadcast; Mike’s skull was found a few hundred yards or a half mile from Diana’s body; and Ruth was found on October 28.

Results: Unresolved - On March 26, 2011, a hiker discovered a partial human skull in the woods off State Route 7 in Lewis County near Mineral, Washington, about a mile from where Diana's body had been found. Police searched the scene and discovered a lower jawbone with teeth, a rubber boot, and some pieces of clothing. In April, the remains were identified as Mike’s through dental records. Police also found a heavily weathered identification card nearby, but they do not know whose it is or whether it is connected to Mike.
No other traces of Mike have been found, and his cause of death could not be determined. However, they were able to rule out a gunshot wound to the head. His gun was reportedly never found. According to the hiker who found the skull, there was a large hole in its side. Following this discovery, authorities said Mike might have been a homicide victim. They speculated that an unknown serial killer may have been responsible for all four deaths.
In November 2011, detectives submitted DNA found at the crime scenes to the Washington State Patrol crime lab for analysis. They also released a detailed description of the sock found wrapped around Diana’s neck. It was a white, stretchy, knee-high basketball sock, about three feet in length, with dark, navy-blue colored rings around the top. It was a “little dingy.” When it was found around her neck, it was tied in multiple knots.
In 2020, Pat Beall, a Lewis County cold case detective, was interviewed for the “Washed Away” podcast. He said the police still believe that Mike is a suspect in Diana’s murder. He said that Mike was hostile towards Diana, harassed her, and cut her tires on several occasions. She had also dated another man prior to her death. Detective Beall said that Mike was under court-mandated counseling and was prescribed Ativan to help with his anger issues. However, one of its side effects was “fits of rage.”
Detective Beall claimed the last time Mike was seen was when he visited Lloyd’s house that morning. Crystal was with him, but Diane was not. Detective Beall also said that a tree was found growing through Mike’s skull, which led them to determine that he had died around the time of his disappearance.
Detective Beall stated they were trying to get a DNA profile from Mike’s teeth to compare to a DNA profile found on the ligature used to tie Diana’s hands. He also stated that testing was being done on evidence from Stephen and Ruth’s case. He said he was not sure if the cases were connected, noting that the socks were not from the same “batch.” He said that if the DNA does not match Mike, then they will try to compare it to any DNA that may have been found at the other crime scene.
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