He was asked by his police chief to audit the case in 2005 and was given full access to the file and evidence.
Low also said: “One thing about report writing is the human error factor – misheard, misunderstood, transposed thoughts and forgotten details.
“They [the police department] were led astray. I might have fallen for it, too, but now I think it’s a homicide, and I do think the case should be reopened.”
The Seattle Police Department told the Daily Mail: “Kurt Cobain died by suicide in 1994. This continues to be the position held by the Seattle Police Department.”
Low cited what he described as anomalies in blood evidence, the force of the shotgun wound and inconsistencies between autopsy findings and police reports.
He said: “I’ve read the case, and I can tell you what the evidence says because that’s what I did for a living, and it does say not suicide.”
Low also questioned early public statements made at the scene by police spokesperson Vinette Tishi alongside medical examiner Dr Donald Reay.
In a recorded interview at the time, Vinette said: “It was obvious this man is dead from a shotgun wound to the head … now there was a suicide note left inside the, then house.”
Low said: “I think they went in with their mind made up. It was a suicide.”
He also raised concerns about the condition of Kurt’s hands in scene photographs and the level of heroin recorded in medical findings.
He added: “The birdshot went into his skull and really did a number. All the pellets were accounted for, but the impact would have been so forceful that it would have produced a significant spray, not just a little, a large spray.”
Kurt’s body was discovered three days later in a greenhouse attached to his Seattle home by an electrician installing security lighting.
The King County medical examiner ruled the death a suicide, stating Kurt had used a Remington Model 11 20-gauge shotgun found in his arms, with a note located nearby.
That ruling has stood for more than three decades.