Detectives are trying to unravel how a high-flying dentist ended up attacking two strangers before being shot dead by police in Sydney’s Potts Point.

Steven Lin, 41, was a best-selling author and social media star, but the father-of-six recently spiralled with drug use and brushes with the law.

The Central Coast dentist had a brief brush as a regular on speaking tours with his message focusing on clean living and oral health.

His life ended on Tuesday when he was shot dead by police after investigators say he randomly attacked two women then came at officers with a knife.

“A taser was deployed. It was ineffective. One round was discharged by a police officer striking the male,” Assistant Commissioner Peter McKenna said on Tuesday.

Lin had broken into the Potts Point apartment building and, in a bizarre chain of events, was found going through residents’ laundry.

When he was approached, police say he pulled out the weapon and attacked a 47-year-old woman then a 57-year-old woman, neither are believed to have been known to Lin, before jumping out a window.

Court documents have revealed Lin’s fall from grace in recent years, with drug use and charges of assault and intimidation.

One of the questions investigators are now trying to answer is what Lin was doing at the apartment building in the first place.

Police are now working to retrace his steps, trying to figure out what state of mind the 41-year-old might have been in the days and hours leading up to yesterday’s attack.

“The way and how this unfolded will be thoroughly investigated,” McKenna said.

Police have declared a critical incident investigation into the shooting.

“The investigation will be subject of an independent review by the Professional Standards Command and overseen by the Law Enforcement Conduct Commission,” officers said in a statement.