217: Diabolical Mistress Sets Up Her Husband For Murder?! | The Disturbing Case of Shawna Nelson

The tragic murder of Heather Guerrero, a dedicated and well-liked supervisor at a Colorado credit union, shocked her co-workers and prompted a swift police response. The case quickly revealed evidence of a premeditated and targeted attack.

Heather Guerrero was a dedicated, well-liked employee at a Colorado credit union who was brutally murdered in the parking lot after her shift.

On January 23, 2007, Heather Guerrero was finishing up her shift at the Colorado State Employees Credit Union, a place where she was known not only for her role as a supervisor but also for her involvement in her local church. She stayed in the parking lot after work talking with her co-workers when she was approached by an individual later described as looking like the Grim Reaper, clad in a mask and hood. The assailant commanded Heather to get on her knees and then uttered "you ruined my life," before shooting Heather twice in the head.

The shooting happened in front of Heather's coworkers, who were too shocked to attempt CPR and called 911 for help.

Multiple 911 calls were made as Heather’s coworkers, too shocked and terrified to perform CPR, attempted to get help. Amidst this chaos, they reported someone had just tried to murder their co-worker. Unfortunately, by the time the police arrived, Heather was in a critical condition and despite the rapid response, Heather died within the next half hour after the attack.

The crime scene evidence and witness accounts pointed to a premeditated, targeted attack rather than a random act of violence.

The shooter wore a black hooded robe and mask, suggesting they planned the attack in advance.

The shooter wore a mask and hood, immediately leading authorities to believe the attack was premeditated. The clothing and disguise were meant to conceal their identity, with the assailant reportedly running down an alley, suggesting they had planned an escape route. Furthermore, police officers found a Grim Reaper mask and a black cape inside a truck belonging to Shauna Nelson, a 911 dispatcher who was known to be having an affair with Heather’s husband Ig—both the mask and cape matched what witnesses described.

The items found in Shauna's possession, which she dismissed as "just an old Halloween costume," incl ...

The case under scrutiny reveals a tangled network of relationships, betrayals, and complex motives amongst the key figures, all revolving around a tragic murder.

Shauna Nelson's affair with Ig Guerrero

Shauna Nelson, a 911 dispatcher, engaged in a three-year affair with Ig Guerrero starting in 2004. Both Shauna and Ig were married—Shauna to Ken Nelson, a police officer, and Ig to Heather Guerrero. The affair remained a secret to their spouses but was an open secret among their coworkers. They exchanged numerous threatening messages, and Shauna even got a tattoo with a name referring to Ig, suggesting an unhealthy obsession.

The affair becomes dangerous

Eight years into her marriage, Shauna developed a close relationship with Ig Guerrero, which eventually turned romantic and sexual. They each complained to each other about their respective spouses, building a bond that led to Shauna saving Ig's number under a false name in her phone and Ig surprising his wife Heather with flowers possibly out of guilt.

Shauna hid her affair with Ig from Ken for years despite multiple pregnancies. Eventually, Shauna could not keep the relationship secret and placed Ig's name on the birth certificate of her second child. When the affair was exposed, Ken confronted Shauna about her relationship with Ig.

Loyalties and threats intertwined

The complex web of relationships and infidelity created a thick plot of potential motives for Heather Guerrero's murder. Shauna's anger ...

Shauna Nelson faced trial for the first-degree murder of Heather, where a combination of testimonies and a lack of credible defense led to her conviction and a lifetime prison sentence without the possibility of parole. The aftermath of this crime was marked by additional tragedy.

Shauna was charged with first-degree murder for Heather's killing, with extensive evidence implicating her in the crime.

Evidence critical to the prosecution's case against Shauna included the fact that the murder weapon was never recovered, yet her DNA and other physical evidence tied her to the scene. Furthermore, Shauna's close friend Michelle Moore, who had inside knowledge of Shauna's affair, confessed during an interrogation that Shauna had premeditated the entire murder. Michelle described in detail how Shauna planned the crime and sought advice on how to carry it out without getting caught.

The murder weapon was never recovered, but Shauna's DNA and other physical evidence tied her to the scene.

Without the murder weapon, the case heavily relied on the physical evidence that linked Shauna to the murder scene. This evidence played a crucial role in her conviction, demonstrating her presence at the site of Heather's killing.

Shauna's friend Michelle testified that Shauna had specifically sought her advice on how to commit murder without getting caught.

Michelle, having been charged with conspiracy to commit first-degree murder and criminal attempt to commit first-degree murder, testified against Shauna. She revealed that Shauna inquired about ways to commit the murder without detection.

Shauna mounted an elaborate defense at trial, claiming she was innocent and the victim of a revenge plot by her former lover Michelle.

Shauna claimed she went out to buy wine and was unaware of Heather's death at the time of her arrest. She alleged that Michelle, as a result of their ended sexual relationship, sought revenge and was the actual perpetrator of the murder.

However, the jury did not find Shauna's story credible and convicted her of first-degree mur ...