In 2013, Mullins's remains were found tied to a 25-pound anchor in four feet of water off Emerson Point, Florida.
While the authorities declared Mullins's death as a suicide, there's been some speculation about his former neighbour and family friend Damon Crestwood, who allegedly displayed suspicious behaviour following the incident.
So, who was Damon Crestwood exactly?
Here's everything you need to know about Damon Crestwood, featured in the Netflix docuseries.
Who was Damon Crestwood?
Damon Crestwood was the neighbour of Manatee County librarian Patrick Mullins, whose body was found in 2013.
Crestwood met Gray Mullins, Patrick’s brother, in the late 1980s or early 1990s, and their friendship grew and extended to their families.
Crestwood would reportedly spend holidays such as Memorial Day with the Mullins family, but the documentary series claims that the professional chef’s reaction to Patrick’s passing was still almost "proportionally" overwhelming.
Was Damon Crestwood involved in Pat Mullins's death?
It's unknown. Patrick Mullins's death was ruled a suicide, but Crestwood's behaviour after the incident raised a few eyebrows.
Despite being neighbours and family friends, Mullins and Crestwood were not believed to be particularly close, yet Crestwood allegedly appeared very shaken by his passing.
According to Gray, Damon would "break into tears and then uncontrollable sobbing" after Pat had passed away.
Pat's wife Jill added that Damon admitted to her that he "would go and look out along the Manatee River and cry and sob for hours".
During Memorial Day in 2013, Damon also publicly tied a rope around his waist in a very similar manner to the rope Pat was bound in when he was found dead.
As well as this, Crestwood reportedly experienced mental breakdowns every January around the anniversary of Pat's death.
Is Damon Crestwood still alive?
Damon passed away in 2017. He reportedly died from a drug overdose.