In Richmond Beach, WA, N.W. 192 Street , a close-knit community, in 1975, Dinah Peterson was a pretty, 16-year-old girl who met a dreadful end on, of all days, Valentine’s Day. Someone literally stabbed her in the heart in her own backyard and left her there to bleed to death. It was her father who found her on the side of the house, lying on her back, staring lifelessly at the sky above. Policemen arrived quickly to find a devastated family. Dinah’s mother, Leanne, had locked her out of the house the night she died. She was tired of Dinah sneaking out of the house to see Diner, her boyfriend. Dinah had even snuck out to see Diner when she was at home babysitting her younger siblings, leaving them alone. Like little Leslie Mahaffey, the murder victim of Paul Bernardo and Karla Homolka, it was a Tough Love-type approach to establishing discipline.
The coroner took his time arriving at the scene. The police didn’t pay much attention to the blood around Peterson’s body. Stupidly, the coroner thought Peterson had fallen off the balcony above her. Now does a fall from a balcony onto grass and autumn leaves end up in a bloody mess on the lawn (scratch head)? Already the investigation wasn’t shaping up to be very successful. Tim Diner lived next door to the Petersons. Two doors down Jim Groth lived. Diner and Groth were immediate suspects in the case.
Diner was the neighbourhood partier. His door was always open and people came and went, drinking and having a good time. Groth on the other hand, wasn’t well-liked. He was described as “quirky”. He was a “kid who showed up and you just couldn’t get rid of him.” On Valentine’s Day, in the evening, Groth simply showed up to see Dinah and her friend Tricia. The two girls quickly tired of his unwanted company and left the house without him to get a pizza. Leanne ventured downstairs to find Groth still seated on the couch, waiting for Dinah to return. Leanne told Groth to leave which he did As Dinah and her friend walked home from the pizza restaurant, a friend, Kathy Strunk, offered the girls a ride home. It was late in the evening when Dinah arrived home. As she lay in bed reading, Leanne heard what she thought were “playful screams,” coming from the yard. Looking out the window, she saw shadows and went outside to find her daughter. The door was open. Leanne called for Dinah but Dinah didn’t answer. Leanne let Dinah’s dog out then locked the sliding glass doors to the basement. Naturally, Dinah wasn’t able to walk around to the front door and ring the bell. She was dying in the backyard.
When police removed Peterson’s body they discovered a large hunting knife in her back. So much for falling off the balcony. They conducted an extensive investigation into Dinah’s death, taking casts of shoe prints near Dinah’s body, samples of skin beneath her fingernails, and several photographs of the crime scene. Police investigated Dinah’s father, who had a hunting knife in his workshop. Naturally he fell under suspicion but there was no further investigation involving Dinah’s father. That morning, Groth and Diner were interviewed about their whereabouts the night of the murder. Groth informed police that after Leanne told him to leave he went to a bowling alley, then went home to bed. Diner stated he had visited a friend, got home at 11 p.m. and heard a dog barking, but he hadn’t connected it with Dinah’s dog. Without a warrant, police searched Diner’s house and found a pair of pants with blood on them. Rumours had run around the neighbourhood that Diner liked to go out and “kill animals,” and that “he and his friends would beat people up when they would have parties [at Diner's house].” The knife used to kill Dinah belonged to Diner. Major break in the case, no?
After Diner’s arrest, he got a lawyer and stopped talking to police. Investigators didn’t have enough evidence to make an arrest and Diner was free to walk. Once when she saw Diner outside working on his car Leanne admitted “I wanted to go out and cut his heart out.” Groth and Diner took polygraph exams. Both failed. Groth changed his story about having been at the blowing alley when Dinah was murdered. He admitted on his way home, he crossed through the Peterson’s yard and saw Dinah lying face-down on the grass. Police had found the body lying face-up. Uh-oh. Bit of a Freudian slip. Investigators took a closer look at Groth. He’d always had a strong crush on Dinah, who didn’t return the interest. Police now had two potential suspects. Investigators spoke to friends of Dinah’s and Diner’s. One girl informed police that after Dinah’s murder, Groth had held a hunting knife at her, hitting her side with it and declaring “gotcha!” Eric Hansen, a classmate of Groth’s claimed Groth assaulted him at his father’s business. On his way out of the store Groth commented, “If you tell anyone about this I’ve killed one girl, I can kill again.” Now if that doesn’t stir the pot on the stove.
Idiotically, the Juvenile Department at the police station handled the report and neglected to hand it onto the homicide division. Seriously. Nothing came of Hansen’s complaint. For whatever reason, police had Groth take another polygraph test and this time he passed. Groth was now excluded as a suspect based only on a polygraph test. Apparently, it didn’t occur to police to ask Groth why it was that he left a good friend on a lawn with a knife in her back, and simply strode home (scratch head). Then two weeks after Dinah’s murder the main investigator was removed from the case and re-assigned to a task force that was hunting for the notorious serial killer Ted Bundy. If that don’t beat all. The focus on the Bundy case meant Dinah’s murder fell off the radar. The murder wasn’t “newsworthy” and investigators turned their interest elsewhere. Within months of Dinah’s murder, the Petersons moved out of the neighbourhood, unable to bear the painful memories of their child’s gruesome death. Now and then police placed Diner under investigation, finally driving him out of the neighbourhood. Groth followed soon after. Months passed, until in 1985 the Petersons threw in the towel, believing police would never solve the case. When the Petersons contacted police to retrieve their daughter’s clothing and belongings, they were told a sergeant had thrown it away in a bid to clean out the murder case storage room. All of the evidence that could have been used for DNA testing was permanently lost.(grit teeth)
In 2006 King County detective Jim Allen stumbled across the Peterson case. Intrigued, he re-opened the case. The file was filled with inconsistencies. Returning to the crime scene, Allen began his investigation. Allen believed the investigators were going after the wrong suspect. Diner had been at a friend’s house when Dinah was murdered. He had never changed his story. It was an airtight alibi. Groth, on the other hand, had no witnesses to verify he had been at a bowling alley. He had changed his story on one occasion and especially the position in which the body had been found. A neighbourhood boy had also offered a statement, stating that Groth had run up to him and told the child Dinah had been stabbed. But it wasn’t until 2:30 pm that police knew Dinah had been stabbed. Clearly, Groth was the guilty party. The murder weapon was the clincher. It was the one original piece of evidence that hadn’t been thrown out. Groth could have taken the hunting knife from Diner’s house without telling him. Diner was informed he was no longer a suspect but Diner, who had been a suspect his entire life, wouldn’t cooperate with them. His life had been ruined.
Police found Groth who now lived in Alaska and worked as a fisherman. He was still a violent man, having assaulted many women in his life. Groth was questioned again and he stuck with his story that Dinah had been face-down when he found the body. This time, Groth failed a polygraph test. Allen took another look at the photographs of shoe prints in the Peterson’s yard. Both Groth’s foot prints and Dinah’s interacted in such a manner that it was plausible he had killed her. 30 years after the murder, 59-year-old Jim Groth was arrested for Dinah Peterson’s murder. Groth’s comment was “what will I tell my girlfriend? It’s Chistmas.” At long last, Groth was put on trial for Dinah’s murder. The Petersons were forced to relive their daughter’s last moments alive. No DNA and no confession made the case a tough one. The footprint photographs however were significant and had not been discarded along with other evidence. Somehow, police hadn’t taken photographs or examined the footwear of any suspects or Dinah herself in 1975. That was another major blow to the trial.
The DA’s argument was that Groth’s affection toward Dinah was the catalyst that drove him to kill her. Frequently, he groped her and she would constantly fight him off. Finally the rejection was too much for Groth and in a fit of rage he planned her murder. Waiting for her to return home, Groth emerged from the bushes in the Peterson’s backyard and stabbed Dinah in the back. The first decision the jury reached was 8-4 for acquittal (sense of outrage). Seriously. Juries are a mystery. 3 days later, the jury returned a verdict of first degree murder of “not guilty.” However, on the charge of second degree murder, Groth was found “guilty.” He received a prison sentence of 16 years to life. 34 years had passed. The Petersons could heal. Dinah could rest in peace.