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Foster mom who called 1-year-old ‘worse than the devil’ convicted in his brutal death

Cassidy Renee Lemmon, Vincent Ray Johnson (Boulder County Sheriff’s Office); Thomas Eugene Boyles (

Cassidy Renee Lemmon, Vincent Ray Johnson (Boulder County Sheriff’s Office); Thomas Eugene Boyles (

A 25-year-old former foster mother in Colorado has been convicted of killing her 16-month-old foster child, who authorities say regularly appeared with fresh bruises on his face and head in the months leading up to his death. A Boulder County jury on Monday found Cassidy Renee Lemmon guilty on two counts of child abuse — knowingly/recklessly causing death and one count of child abuse — negligence causing death in the 2019 slaying of young Thomas Eugene Boyles, authorities confirmed to Law&Crime.

Lemmon’s then-partner, 27-year-old Vincent Ray Johnson, was also arrested following Thomas’ death and charged with the same three counts of child abuse. He struck a deal with prosecutors, pleading guilty to one count of child abuse — negligence resulting in death, a Class 3 felony, and agreed to testify against Lemmon in exchange for a 12-year prison sentence. The other two child abuse charges were dropped, per the plea deal.

“This defendant and her co-defendant extinguished the life of a beautiful little boy. We appreciate the jurors who gave up more than two weeks of their summer, worked through evidence and expert testimony, and reached the right verdict,” District Attorney Michael Dougherty said in a statement emailed to Law&Crime. “From the beginning of this case, the detectives with the Longmont Police Department and our prosecution team were determined to secure justice for Thomas. They did an outstanding job with this very tragic case.”

According to court documents obtained by Law&Crime, officers with the Longmont Police Department and paramedics at about 5:47 p.m. on April 22, 2019, responded to a 911 call regarding a 1-year-old male child who was not breathing at a home located in the 3200 block of Lake Park Way.

Upon arriving at the scene, first responders located Lemmon performing CPR on Thomas and noted that the boy was only wearing a diaper and had visible bruising on his body and face. Fire Department medical personnel immediately transported Thomas to Longmont United Hospital via ambulance. Due to the severity of his injuries, Thomas was airlifted to Children’s Hospital in Aurora, Colorado, later that evening for more specialized treatment. Unfortunately, the little boy succumbed to his injuries and was pronounced dead at about 4:50 p.m. on April 24.

One of the paramedics told police that before she asked Lemmon anything, the defendant approached her and said that Thomas was “under medical care for the bruises.” Several other medics and officers described the home as being “dirty” with “an overwhelming strong odor of feces and cat urine.”

At the hospital, doctors told investigators that Thomas’ injuries included “intracranial hemorrhage, multiple rib fractures, liver and spleen injuries” as well as a subdural brain bleed and spinal fracture, all of which appeared to be from child abuse. Doctors also noted that Thomas had broken ribs in different stages of healing, which is a typical indicator of long-term abuse.

In an interview with investigators, Lemmon said Thomas had been sick for the previous two weeks and indicated that he had thrown up twice before he stopped breathing. When the doctor came in and mentioned that Thomas had a brain bleed, Lemmon told the detective that Thomas had also struck his head on a toy chest earlier in the day and then “fell down face first on the ground and laid there for a short while.”

Johnson admitted that on the day of Thomas’ death, the boy “wouldn’t stop whining/crying,” so he grabbed him by the leg and “spanked Thomas on the butt and told him to be quiet.” When asked about the boy’s broken ribs, Johnson said he “doesn’t know his own strength” and may have “squeezed Thomas too tight.” Johnson then suggested the broken ribs were from CPR.

Both foster parents also told investigators that Thomas had “sensory problems” and would regularly “bang his head” on different things and injure himself.

Text messages from Lemmon also revealed that she was growing increasingly frustrated with Thomas.

“He doesn’t f—— listen so hes not allowed to do some things. It’s not my fault hes stupid,” she wrote a few weeks before the boy’s death. “I keep him away from doing those stupid things so he’s not in trouble all the time and pissing me off.”

In another message, she referred to Thomas as being “worse than the devil.”

However, doctors said the boy’s injuries were “too severe” to be caused by “self-injurious behavior,” noting that the child had liver and spleen lacerations and “a massive amount of blood in his belly because of these injuries.” In the affidavit, police wrote that the doctor told them, “This is a battered baby.”

A subsequent autopsy determined that Thomas’ death was a homicide caused by “blunt force injuries.”

After being confronted with medical evidence contradicting their stories, Johnson told police that Lemmon would regularly get frustrated with Thomas and “would hit him and throw him.” He said in the weeks leading up to Thomas’ death, Thomas became more and more despondent.

“After a while, the last couple of times she tossed him, Thomas would just land and sit there with his hands in his lap,” Johnson said, per the affidavit. He also claimed that after being thrown, Thomas would “just be depressed and would cry to himself” because he had accepted “he’s not getting any love from the person he wants to be loved by.”

He also claimed that on the night Thomas died, Lemmon got “black out drunk” and told him “I’m really sorry.”

Lemmon is scheduled to be sentenced on Oct. 30. She is facing between 16 and 48 years in prison, per the District Attorney’s Office.

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Jerry Lambe is a journalist at Law&Crime. He is a graduate of Georgetown University and New York Law School and previously worked in financial securities compliance and Civil Rights employment law.