Forensic Files - Season 1, Episode 5 - Planted Evidence - Full Episode

Summary

In a groundbreaking murder case, Denise Johnson’s body is found in a remote area near Phoenix, with evidence pointing to local trucker Mark Bogan. Though Bogan denies involvement, circumstantial evidence, including a missing pager and wire used for bondage, leads investigators to focus on him. The key breakthrough comes when plant DNA from Palo Verdes trees, found on seed pods in Bogan’s truck, is used to link him to the crime scene. Despite a lack of traditional evidence, DNA testing on the pods becomes the critical piece that secures Bogan’s conviction, marking the first use of plant DNA in a criminal trial.

Takeaways

• 😀 A motorcyclist discovered the body of Denise Johnson, a young woman who had been beaten, strangled, and possibly raped in a deserted area near Phoenix.
• 😀 Investigators found important evidence at the crime scene, including a pager, clothing, and evidence of an altercation, but no direct evidence of the killer's identity.
• 😀 The victim, Denise Johnson, was identified through fingerprint analysis. She had a history of drug-related issues and a reputation for short-changing truck drivers, earning her the nickname 'Twist Momma.'
• 😀 Mark Bogan, a trucker, was identified as the last person to have interacted with Denise Johnson the night before her death, but there was no clear evidence linking him to the crime.
• 😀 The investigation revealed that Mark Bogan had a scratched face, but the absence of blood or skin under the victim's fingernails made the link to him unclear.
• 😀 An unusual discovery was made when investigators found two bean pods from a Palo Verdes tree in the back of Bogan's truck, which led to further scrutiny and a unique approach using plant DNA.
• 😀 The Palo Verdes tree DNA analysis, a first in criminal investigation, was used to match the pods from Bogan's truck to the tree near the crime scene, providing crucial evidence linking Bogan to the murder.
• 😀 DNA testing on the pods from the Palo Verdes tree helped to definitively prove that the pods found in Bogan's truck matched the tree near where the body was discovered, eliminating the possibility of coincidence.
• 😀 The DNA evidence was accepted as reliable and valid in court, despite being the first instance of plant DNA being used as evidence in a criminal trial.
• 😀 Mark Bogan was convicted of first-degree murder and sentenced to life in prison without parole, despite maintaining his innocence, and his appeal is still ongoing.

Q & A

What were the key pieces of evidence found at the crime scene where Denise Johnson's body was discovered?

The key pieces of evidence included a nude body, a t-shirt wrapped around the neck, shoelaces and picture hanging wire used to bind her wrists and ankles, a syringe, articles of clothing, and a pager found near the body.

How did investigators identify Denise Johnson?

Denise Johnson was identified through fingerprint analysis, which confirmed her identity as a 30-year-old single mother from Phoenix.

What was Denise Johnson's background and lifestyle like?

Denise Johnson lived a troubled lifestyle, spending time with people who used drugs and engaged in partying. She earned her living through activities such as short-changing truck drivers in drug deals and earned the nickname 'Twist Momma.'

What was the initial suspect's explanation regarding his encounter with Denise Johnson?

Mark Bogan, the initial suspect, explained that he met Denise Johnson at a phone booth and gave her a ride. They had consensual sex in his truck, but a brief scuffle occurred when she attempted to steal some of his items, after which she left on foot.

What unusual finding did detective Charlie Norton discover while revisiting the crime scene?

Detective Charlie Norton noticed a fresh abrasion on a Palo Verdes tree near the crime scene, which he photographed and took samples from, unaware of its potential significance at the time.

How did the Palo Verdes tree and its seed pods become important evidence?

The seed pods from a Palo Verdes tree found in Mark Bogan's truck were matched through DNA testing to the tree near the crime scene. This unique DNA fingerprinting of plant material was used to link Bogan to the crime scene.

What scientific breakthrough allowed investigators to use plant DNA as evidence in this case?

The scientific breakthrough involved DNA testing of plant material, specifically the use of RAPD (Randomly Amplified Polymorphic DNA) to match the DNA from the seed pods to the specific tree at the crime scene.

What were the challenges in using plant DNA as evidence in a criminal trial?

The main challenge was the novel use of plant DNA as evidence, as it had never been used in a criminal trial before. Legal debates were held to determine if the DNA analysis could be considered reliable and valid scientific evidence.

What was the prosecution's strategy for linking Mark Bogan to the murder?

The prosecution used circumstantial evidence, including the missing pager, wire used for bondage, and an eyewitness who saw a white truck matching Bogan's near the crime scene. The most critical evidence was the plant DNA linking Bogan's truck to the Palo Verdes tree at the crime scene.

What was the outcome of the trial, and how did the court rule on the use of plant DNA evidence?

Mark Bogan was convicted of first-degree murder and sentenced to life in prison. The court ruled in favor of admitting the plant DNA evidence, setting a legal precedent for the use of plant DNA in criminal trials.