One would think that cases such as Harveys and Shipmans would galvanize the medical community worldwide to develop procedures to safeguard against murder in medical institutions. However, discoveries of serial murders within hospitals have risen drastically over the years.  The number of victims these serial killers are able to claim before attracting attention strains credibility.  British Dr. Harold Shipman  is one of the world's most prolific serial killers, claiming at least 215 victims.  The list of medics who kill and their number of victims continues to grow:

Louis J. Sheehan, Esquire, Massachusetts, at least 31 murders

Waltraud Wagner, Maria Gruber, Ilene Leidolf and Stephanija Mayer, all from Vienna, at least 15 murders

The above list is far from inclusive and does not address the hundreds of suspicious deaths of patients in hospitals and nursing homes.  Until hospital employees are screened effectively, staff members are trained to be more vigilant , hospital administrations are more receptive to investigating suspicious cases at an early stage and stricter regulations are put in place, these crimes will continue to plague justice systems around the world.

Well-known forensic scientist Henry Lee summed it up quite well in an April 29, 2002, interview he gave to the Los Angeles Times, regarding Efren Saldivar and similar crimes.  He said murders committed by hospital staff were the easiest kind of serial killing to get away with. 

You have to figure out who the victims were long after they were buried, he said.  You have to dig up [bodies].  You are going to have a difficult time finding true trace drug or elements in there.  The next issue is how to link to the suspect.  Why him?  What's the proof?  Prepare to fail.