The forensic psychiatrist who assisted in the investigations into the death of American child beauty queen JonBenet Ramsey has been shot dead outside his office.

Dr. Steven Pitt, 59, helped investigate the high profile 1996 murder case as well as a string of other killings in the Phoenix area more than a decade ago.

In JonBenet’s case Pitt believed the pineapple found in the six-year-old’s digestive tract, which her mother denied she ate, was proof of a family cover up.

He was leaving his office when witnesses say they heard a loud argument then gunfire as he was shot on Thursday.

Dr. Steven Pitt, 59, who helped investigate the high profile 1996 death of child beauty queen JonBenet Ramsey, has been shot dead outside his office on Thursday, pictured in June 2007

Phoenix Police found Pitt, left, dead from a gunshot wound at 5:23pm Thursday. Investigators have released a sketch of the suspect behind the shooting, who fled the scene, right

His office is located near the intersection of 71st Street and Bell Road in Scottsdale, a suburb of Phoenix.

Phoenix police say Pitt was 'critically wounded' when officers first arrived on the scene, according to ABC15.

A flyer from the police department says he was found deceased from a gunshot wound Thursday at 5:23pm.

Phoenix police spokesman Sgt. Vince Lewis says he has no information on whether the killing is connected to his work, according to Tuscon.com.

'We are not ruling anything out, but at this point, a loud argument probably suggests they knew each other either professionally or personally,' Lewis said.

Investigators have released a sketch of the suspect, who fled the scene.

Police describe him as a Caucasian man who is bald and was seen wearing a dark-colored hat with a short brim.

Pitt is known for assisting in six-year-old JonBenet's death investigation after she was found brutally murdered in her Boulder, Colorado home.

The psychiatrist believed the pineapple found in JonBenet's digestive tract was a key to the investigation as it was proof she ate not long before she died.

Her mother Patsy said that the beauty queen hadn't eaten any fruit before she went missing, however the mother's fingerprints were found on the fruit bowl, raising Pitt's suspicions towards a cover up.

Pitt gained recognition for working on a number of high profile cases including JonBenet's death, Phoenix's Baseline Killer in 2006, and the 1999 Columbine High School shooting

He was shot outside his Scottsdale, Arizona office, pictured above Thursday evening

Police gathered outside the office complex after gunfire rang out and Pitt was found dead

The suspect fled the scene, above, as police now hunt for information on the suspected killer

A colleague of Pitt speculates a person connected to one of his criminal cases could be behind the shooting

Phoenix Police put up this flyer in pursuit of the suspect, a white male, who fled the scene Thursday evening

'The fingerprints on the bowl or cup that were used to give JonBenét the pineapple were Patsy’s fingerprints,' Pitt formerly said to People Magazine.

'It suggests someone is not telling the truth about what happened at that home that night,' he added.

A prosecutor later cleared her parents and brother in 2008 based on DNA evidence.

Pitt also aided in the investigation of the Baseline Killer in Phoenix in 2006, hunting down a man later convicted of killing nine people.

He also consulted in the 1999 Columbine High School shooting.

His most recent case was on a spree of shootings in the Maryvale area that started in April where six have been shot and one victim shot last month died from their injuries this week.

A friend of Pitt and a fellow Phoenix psychologist David Weinstock told the Arizona Republic he speculates a person connected to one of Pitt's criminal cases could be behind the shooting.

'I could be wrong, but the timing and circumstances sound a lot like someone who was waiting outside his office for him,' Weinstock said in an email.

'I suspect this was one who either got out after Steve helped put him away or someone whose case he was working on who felt threatened about what Steve could do,' he added.

Pitt is known for assisting in the investigations of the 1996 death of American child beauty pageant queen JonBenet Ramsey, pictured above

Ramsey was a beauty pageant queen who was murdered in her home Christmas evening

Ramsey's home pictured sectioned off by police after she was found dead inside on Christmas night in 1996

Her mother Patsy Ramsey holds up a reward sign for information on her daughter's killer on May 1, 1997 after four months of media silence in light of her daughter's death

Weinstock added that he and Pitt had previously discussed the risks they face in their professions.

Despite the potential for danger, Pitt had not filed any protective orders as per Maricopa County Superior Court records, according to AZCentral.

Pitt worked as a Clinical Associate Professor of Psychiatry at the University of Arizona College of Medicine in Phoenix at the time of his death.

'Dr. Pitt was beloved on this campus and went above and beyond mentoring our students and lecturing to our community,' Dean Guy Reed said in a statement in light of Pitt's death.

He gained recognition in his career for his work in forensic psychiatric evaluations and has appeared on a myriad of news shows to talk about his investigative work on his various high profile cases.

Joann Sanchez, the center manager of the complex that houses Pitt's office, says Pitt was a close friend who she called 'The Tin Man' because he had the 'biggest heart ever'.

Bobette Siegel, a licensed clinical social worker who also worked in the building said everyone in the complex knew Pitt.

'It’s such a loss for his professional community, the forensic community, his family … and for me personally, she said.