Such crimes are "particularly heinous, and all are senseless", said Shanmugam.
"The law is not a game... My duty is to make sure that these games are not played. So we will change the law."
On Jan 9 this year, Shanmugam said in Parliament that members of the public will have the opportunity to submit recommendations on a review of the Penal Code.
The review will cover introducing harsher punishments for sexual offenders and new criminal offences, he said.
The review will include areas such as repealing laws that criminalise attempted suicide, as well as dropping marital immunity for rape.
The review is set to be completed this year.
Previously, a review of the Penal Code was conducted in 2007. The Parliament had considered 77 amendments and the repeal of four provisions.
A notable decision made by Parliament during the review was the decision to retain s.377A of the code, which criminalises consensual sex between two adult men.
A Penal Code Review Committee was then set up in July 2016, to undertake a review of the Penal Code, and make recommendations on reforming it.
Crossover with other fields crucial to ensure the ongoing relevance of the Penal Code, says law professor
Associate Professor of Law at the Singapore Management University, Eugene Tan said that while he does not deny the underlying importance of deterrence that acts as the rationale behind harsh sentences in criminal law, he believes that deterrence should not be used in a textbook manner, as it may not be wholly applicable to all "crimes".
"Advancements in human psychology and psychiatry and social attitudes have gradually changed our outlook on certain crimes, such as those who attempt suicide."
"While criminal law is, in essence, concerned with crime, the criminal justice process now has to incorporate other disciplines such as such criminology, medical science, the social sciences and urban studies."
"They not only contribute to law and order in our society but, more importantly, inform us how we can go about doing so, while upholding the integrity and dignity of the victims of crime and rehabilitating and reintegrating the offenders," he wrote in a commentary on TODAY Online.
He added that the advent of technological advancements has made "the criminal landscape" in the 21st century "vastly different from what it was in the 19th century".
"Whether it is white-collar crime, sexual offences, or the peddling of deliberate falsehoods designed to cause public panic, technology is increasingly part of the criminal’s arsenal."
"The state has an important role to play in the investigation and prosecution of criminal offences, making criminal law “public” and each of us a stakeholder," he wrote.
Professor Tan also believes that the law should be "clear, precise, and comprehensible to the public", and should not only be seen as the sole purview of lawyers and other legal authorities, as "criminal law is concerned with the regulation of social order and spells out the fundamental requirements for a person’s treatment of others and their property".
He also added that the criminal law system cannot be neglected or be viewed as "less important" than other areas of law, stating that criminal laws should be revised regularly to ensure relevance and fairness, in line with the evolution of society throughout the times.