Dr Dmitriy Nikitin, 41, was gunned down as he walked to his car after finishing his shift at a hospital in Orlando, Florida, where he worked as a leading multiple organ transplant surgeon.

The attacker, Nelson Flecha, spoke briefly to Dr Nikitin before pulling out a gun and shooting him several times.

The 52-year-old transplant recipient then walked to another parking level and turned the gun on himself.

The murder-suicide last Thursday was caught on CCTV cameras in the parking garage at the Florida Hospital in Orlando.

Police said Flecha had laid in wait to ambush the surgeon as he left the hospital.

Flecha was known to have been a former patient of Russian-born Dr Nikitin and had undergone a liver and kidney transplant a year ago.

Dr Nikitin, described as a 'passionate and meticulous surgeon', was married with four children, including a son aged just three.

Despite the life saving transplant, neighbours said Flecha was a 'bitter and angry man'.

He lived alone in a small flat in Orange City and never seemed happy, even though he had been given a new lease of life with the double transplant.

One neighbour said: 'Given what this guy had been given you would think he would smile, but he never did.'

Police say they are investigating whether Flecha could have been suffering from complications after the operation.

Investigators said they will ask a court to release medical records to find out more about Dr Nikitin's relationship with his killer. Read More