What makes a nurse a serial killer? The five characteristics that define our 'Angels of Death'

Victorino Chua has been found guilty of murdering two and poisoning 19 of his patients

Victorino Chua has been found guilty of murdering and poisoning hospital patients in Stepping Hill hospital. (Rex features)

Victorino Chua, the nurse found guilty of killing two patients and poisoning 19 others may have described himself as having “the devil in me,” but he joins a list of Healthcare Serial Killers (HSKs) that have been found to share common characteristics.

There are between five and nine characteristics identified by criminologists at Birmingham City University that these so-called “angels of death” apparently possess. They were outlined in a study last year, including craving attention and frequently moving between one hospital and another.

Professor David Wilson and Dr Elizabeth Yardley, who passed their findings to Greater Manchester Police when Chua was charged, analysed 16 cases of hospital-based nurses convicted of multiple murder in Europe and North America between 1977 and 2009 using a criminology checklist of 22 “red flag” traits.

The five most common “red flags” identified in HSKs were:

- Higher instances of death on his/her shift

- History of mental instability/depression

- Makes colleagues anxious

- In possession of drugs etc at home/in locker

- Appears to have a personality disorder

The authors expressed caution that increased instances of death needed to be considered against other criteria however, and not simply in isolation.

Other traits included nurses preferring night shifts and having secretive or difficult behaviours.

The most prolific killer the authors identified in their research was American nurse Charles Cullen, who was convicted of 29 murders in 2003 and had portrayed 11 of the “red flags,” though former Leeds-based nurse Colin Norris who was jailed for life in 2008 for killing four people and attempting to murder another, satisfied just two of the red flags, the lowest of all those studied.

The research showed that poisoning was the most common form the HSKs used to kill patients, namely with insulin, though other drugs such as opiates and muscle relaxants were also used.