The 1966 cold case of Valerie Percy

The Cold Case of Valerie Percy: is this the murder weapon?

The Cold Case of Valerie Percy: is this the murder weapon?

The 1966 cold case of Valerie Percy: on September 18, 1966, Valerie Percy (21) was murdered in her parental home in Kenilworth, Illinois, by an unknown intruder. Her case remains cold.

Valerie was the daughter of former senator Charles Percy and Jeanne Valerie Dickerson. Jeanne passed away in 1947. Percy remarried Loraine Diane Guyer in 1950. Together with Jeanne, Percy had twin daughters (Valerie and Sharon) and one son, Roger. With his second wife he had two more children, Gail and Mark.

The authorities ruled out that this crime concerned a burglary gone wrong as nothing was stolen. The attack on Valerie was intense and suggests a personal attack. On the left side of her face, she had multiple lacerations and her left eye was closed. Her right eye was partly open. A pool of clotted blood stuck to the right side of the back of her neck. She was disfigured beyond recognition. When Valerie was found all her vital signs were negative.

The cause of death was a fractured skull (left side) and 14 stab wounds. Two stab wounds were in her abdomen and they had penetrated her liver. One stab wound went through her left breast and penetrated her heart. One stab wound in her right breast reached her lung. Another stab wound went through her throat hitting her spinal column. The coroner said that there were several cuts to her face. These were most likely inflicted with a double-edged knife. There were several abrasions like tooth marks on two fingers on her right hand. The weapon used on her skull left triangular impressions.

Valerie Percy’s murderer left five bloody palm prints on the banister and a black leather glove outside the mansion. If properly preserved, the glove should be treated with the M-Vac System for touch DNA. The killer also left footprints at the Percy home leading to the beach. Three days after Valerie’s murder, police found a bayonet in Lake Michigan (see photograph above). In 1966, none of this was connected.

The authorities canvassed the area. Since the family dog didn’t bark or cause any other kind of alarm, police think that the killer was familiar with the area, the Percy estate, the inside of the house, and possibly the dog and Valerie herself. Theories galore about what and why this happened: a politically motivated attack to stop her father’s career, a jilted lover, a professional killer, a professional burglar caught by Valerie, and even the mob gets a mention.

The authorities now believe that William Thoresen III was involved in this cold case. Kenilworth police said that Thoresen “was never cleared from involvement in the Percy case” and that his possible involvement is now considered “undetermined.” Glenn Wall dug into the case and found several connections between Thoresen and the Percy case. “Most significantly, authorities believe the murder weapon was a serrated bayonet.

William Thoresen’s arrest record includes charges in Chicago and Los Angeles for aggravated assault and the possession of illegal weapons including bayonets. FBI records show that it was Thoresen’s probation officer in Los Angeles who alerted the Chicago police. The authorities eventually found Thoresen in New York. He claimed that “he could be of no help in the Valerie Percy case and refused to be interviewed or answer any questions about the Percy case or any other matters.”

Four years later, Thoresen was killed by his wife Louise on June 10, 1970. “She was immediately taken into custody and was not released from jail until after she was acquitted in Nov 1970.” Louise was acquitted after telling the jury that her husband killed many people. William Thoresen III, the son of a Kenilworth industrial tycoon, is described in one of the FBI report as “violent, a mental case… armed and dangerous.”

Thoresen grew up in the same neighbourhood as Valerie. In fact, his parental home was less than two blocks away from hers. He knew the area, the layout of the houses and grounds, and where he could walk unseen. Since he was a local, the Percy family dog was most likely familiar with him which would explain why he didn’t bark that night.

The latest information in this case comes from the Percy neighbor Nydia Hohf. Her husband Robert died in 1993. Robert Hohf was the doctor who first examined Valerie. He wrote a detailed report about everything he saw and heard. For years he kept it in a file cabinet after they tried to get police interested right after the murder. Police never interviewed Hohf despite knowing that he was called to come over by Valerie’s father.

After Percy found his daughter dead he called Hohf. According to some, Hohf was the first to enter the house after the murder but the written account seems to contradict that. Hohf’s notes do not solve the case but fill in some gaps in the story.

Some points that stand out to me:

A: The Hohfs wake up because a roof-top burglary alarm goes off. It turns out to be at the Percys. How did that alarm go off? Did someone set it off or was an alarm triggered? Due to the sequences that follow, if it was triggered it was on the way OUT. So, if the house was protected by an alarm how could someone get IN without triggering the alarm?

B: The siren “went quiet, and then sounded again for a couple of minutes, and Dr. Hohf dozed for a minute or two before being awakened by a phone call from Percy.” What kind of alarm exactly was this?

C: Percy calls Hohf to come over to check Valerie who “has been injured.” Percy doesn’t use the words “dead” or “killed.” Maybe he did so as not to shock Hohf. This is unbelievable as Hohf was a professional. Percy mentioned that a police officer was on his way to pick him up (even though he lives nearby?) and indeed one shows up. However, this officer didn’t think it was necessary for the doctor to grab his medical tool bag. He operated from the assumption that Valerie cannot be saved anymore. How did he know? Was he the first to see Valerie and not the doctor? Or, did someone tell the officer that Valerie was dead? What is the correct order here? And why differentiate between the police and a doctor in telling them Valerie is dead?

D: It looks like Hohf immediately knew Valerie was dead when he entered her room. However, the woman that he saw was badly disfigured to the point where Hohf wrote that he didn’t recognize her. I am not sure why but this bothers me.

E: Valerie’s nightgown was raised to her ribs. Was she otherwise undressed? Was she sexually assaulted? A nightgown can be pulled to the ribs if a woman is pulled downwards by her feet. It would look rolled up and about equally high on each side of her body. If the nightgown was shoved up before an assault it would leave a different pattern, more pushed up on the front, longer on the back, and maybe uneven on each side of her body. Do we know what happened here?

F: Concerning the rest of the family: Sharon and Gail were “sitting on their parents’ bed” and the parents were downstairs. Stepmother Lorraine was in a short nightgown and barefoot but father Percy was fully dressed. Did the alarm wake up Lorraine and was she asleep alone? How much time did Percy have to get dressed? If he had time to dress himself why didn’t he slip a bathrobe around his wife knowing that police would arrive soon and she might be uncomfortable seen barefoot and in a short nightgown?

G: A “houseman served coffee” so there were several people in the house. How many family members and how many staff members?

H: Hohf’s impression was that “much had happened before I arrived.” I wish that we had more details to find out why the doctor felt this. His first impressions and gut feelings are crucial here.

The parents’ reactions and actions differ substantially.

Let’s start with the stepmother:

I: Loraine told Hohf that she woke up that night when she heard moaning. The moans were such that she left her bed and tried to find out where they came from. Where was the father at this point? In bed with her? Why didn’t she wake him and let him go with her? That would be a more natural reaction.

J: The moaning comes from Valerie’s room. Apparently, Lorraine knew it wasn’t sexual moaning or else she would not have gone in the room, right? And, if she thought Valerie had a partner in there she would have knocked on the door first, right? But there is no knocking mentioned. We have to assume Valerie’s door was ajar or Lorraine opened it. That also means that Lorraine’s instincts were right (non-sexual moaning) and that clashes with her actions of leaving her bed alone. If a woman wakes up in the middle of the night and hears something, her first reaction is to wake up the one she shares the bed with e.g. the father. Why didn’t she?

K: When Lorraine steps into the room she “saw a figure leaning over Valerie.” From what side? Was Valerie’s bed facing the door? Where did the figure stand? Near Valerie’s head, feet? I wish we had a diagram.

A flashlight beam immediate(ly) was thrown into her eyes,” Hohf wrote, “blinding her so that she was conscious of only a vague form and movement.” Clever move. He continues: “She ran back into her own room and screamed at Chuck that there was an intruder in Val’s room.” So the father was indeed in the master bedroom yet she had not woken him up to come with her in the middle of the night.

L: Now here’s another mind-boggling detail: Hohf wrote “she [Lorraine] turned on lights and the fire siren [so it was manually turned on and not triggered by someone exiting a protected area], Chuck called the telephone operator and asked her to call the Kenilworth police. They arrived in five minutes.”

Is this when the father got dressed? If he knew police would be there soon and he took the time to dress to have his own body appropriately covered then why didn’t he warn Lorraine? A short nightgown and nothing on her feet? A bathrobe would have been the least he could have thrown at her if he got himself slacks, shirt, a sweater and shoes. Aside from that, you think your daughter is mortally wounded and first you dress yourself or do you run to her bedroom?

M: The stepmother thinks that she hears someone dashing down the stairs. Is this when she called for the staff?

N: The stepmother returns to Valerie’s room. Valerie is moaning and “looked very white.” Then she does something I do not understand: “Lon wiped her face with a pillow.” Where was the pillow on the bed and what was Valerie’s body position? What did Lorraine wipe away? Blood, saliva? Did she wipe over the eyes, the mouth, where? Where’s the pillow case? Any DNA?

O: Hohf described Lorrain felt a pulse but it disappeared after a few seconds. Where did Lorraine touch Valerie to feel the pulse? Her neck? Wrist?

P: Loraine told her story “calmly but in somewhat disjointed fashion.” This does not surprise me. But what Hohf infers does: “with speculation that household workers might be responsible.” Would that mean that when Lorraine heard someone dashing down the stairs that she already knew that it was a staff member? Who? Were all staff members eliminated as suspects? Did Valerie have at any point a close relationship with any staff member? Did Lorraine at any time express not being comfortable with any of the staff members? Was anyone fired recently?

Q: Did the father ever enter Valerie’s room? This goes back to the officer telling Hohf that the tool bag was not necessary (e.g. the father told police that Valerie was dead because he had seen it himself or because he believed Lorraine). Hohf wrote. “They must have known she was dead before calling me.” Is Hohf referring to the cops or to Percy?

R: the timeline is unclear. Hohf wrote that he “had a feeling that Percy spoke to Kenilworth police about the need to act quickly since it was only 15 or 20 minutes since his wife saw an intruder flee. At that point, he called Chicago police.” So first we have him call the operator and that operator called Kenilworth Police or did they immediately call the Chicago Police? Maybe this doesn’t matter. When was the Kenilworth PD in Illinois established? If they already existed in 1966, would Chicago automatically take over in cases of homicide?

S: Hohf described that the glass of the “French door, through which the intruder presumably entered, had a ragged break. This differed from impressions in some press accounts that a burglar had cut the glass cleanly.” In some papers it says that the glass was first cut but not wide enough to let someone through. This person then “scored the glass with an X.” If the pane was scored there would be no ragged breaks.

T: A few days after Valerie was murdered, Percy boarded his family on a friend’s private jet for a short vacation in California leaving the house, the scene, Valerie’s body, and the police who were frantically trying to solve this crime. I can see your point: they needed a break from the stress and the mental welfare of the entire family was at stake. OK. But I can see the other side as well: why leave when you know you are in THE most critical phase of the investigation? Not making yourself available to the police is like asking them to find out who stole from your house but telling them not to look around.

Former Chicago Police Detective Joe Dileonardi, who worked on the early phases of the investigation, said that “the family’s leaving at such a critical time did not help the investigation.” I agree. The family could have helped the canvassing process by asking their neighbors to collaborate with police, they could have contacted newspapers and journalists who were already in the father’s network, and they could have helped advance the case by giving interviews or basically by being there.

I am not sure how fast Valerie was buried after her murder but if she was my child, I could not leave her. Even if she was in the morgue, I wouldn’t be able to leave my child. Maybe after the funeral but before? Not a chance.

UPDATE: One of my readers emailed me: “Valerie’s memorial was held onSeptember 20, two days after Valerie’s death. The family left the following day.” Thank you, DY.

If you have read the book by Glenn Wall and can answer any of my questions above, let me know. I will add the book to my reading list.

UPDATE: DY also read the book by Wall and said “He does make a case about who he believes was the killer.” I still have the book on my “to-read” list. Thank you, DY.

RIP Valerie Percy.



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  1. […] September 18, 1966, Valerie Percy (21) was murdered in her parental home in Kenilworth, Illinois, by an unknown intruder. Her case […]