Trigger warning: baby death, violence

Lt. John Faine, who investigated Brooke Skylar Richardson following the death of her baby, is convinced the former cheerleader killed her newborn – despite the fact that she was acquitted of murder.

Faine, who is now retired, is one of the detectives the defense accused in court of “coercing” Richardson into a murder confession two years ago. The Ohio native was 18 when she secretly gave birth in her bathroom and buried the infant in her backyard in the dead of night.

Richardson, who named the child Annabelle, told the court that the baby had been stillborn. Prosecutors, however, claimed the infant had been born alive and accused the teen of smashing her newborn's skull with a rock and burning her body.

Last week, the jury acquitted Richardson, now 20, on charges of aggravated murder, involuntary manslaughter and child endangerment, though they did find her guilty of gross abuse of a corpse. She was sentenced to three years of probation.

Despite her acquittal, Lt. Faine believes she killed the child. “It was just the way she kept adamantly wanting to interject, ‘I didn't kill it. I didn't kill it’,” Lt. Faine told WLWT. “Just from experience, a lot of times over the course of my career, people who are guilty are the ones who are so adamantly, defiantly, telling us overtly, ‘I didn't do this.’ That was part of it, and then, just the secrecy. I still believe that the baby was alive.”

Lt. Faine said he spotted red flags during two interviews, which were six days apart, with Richardson in July 2017. After the first interrogation, she was released without charge. However, during the second interview, she admitted that she may have heard the baby “gurgle” and added, “I think I may have killed her”.

She also told detectives that she might have burned the baby’s body “a little bit.” The defense claimed police were overzealous in questioning Richardson because they were convinced she burned her baby. Meanwhile, Lt. Faine states that before he interviewed Richardson for the second time, a pathologist from the coroner's office verified that “the bones were definitely charred.”

Although initially, she denied hurting or burning the baby, Richardson eventually admitted to doing so. The pathologist, however, recanted the claim that the bones had been burned. The defense also called multiple witnesses during the trial in an attempt to prove she had been coerced into making false statements to police about the circumstances of the baby’s death.

In addition, Cincinnati psychologist Stuart Bassman testified that "Skylar was manipulated" into making false statements during interrogations. He described the teen as vulnerable and immature and claimed that she has a dependent personality disorder that makes her want to appease authority figures, even to the point of making false statements.

The defense accused prosecutors of constructing “a false narrative” to sensationalize the case and claimed the teen hid her pregnancy because she wasn’t aware that she was due so soon. They attributed her behavior to her fear of being found out.

“What started as an 18-year-old high school girl who was frightened and saddened because of giving birth to a stillborn baby whom she named Annabelle and then telling her doctor of the stillborn and burial in the backyard turned into something sinister and grotesque,” one of her defense attorneys told the court.

During sentencing, Richardson apologized to the baby’s father, Trey Johnson, saying, “I am sorry. I can sometimes be selfish, but I’m getting better. I’m forever sorry."

RELATED: Ohio Cheerleader Accused Of Murdering Newborn Sentenced To Three Years Of Probation

Despite her acquittal, Judge Donald Oda told Richardson during sentencing that she acted with "grotesque disregard for life.” He also said he was restricted by law as to the sentence he could pass down. “In all of this mess that we have in this, what often gets overlooked is how precious life is. It should be protected. It should be guarded," Oda added. "Some people are inclined to think to themselves, you know, 'this is America, we kill unborn babies every day,' but I don’t look at it that way."