We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

What is a Preliminary Investigation?

Mary McMahon
Updated: May 16, 2024

A preliminary investigation is an inquiry conducted by law enforcement representatives to gather more information about an allegation. The purpose of the inquiry is twofold: it is designed to determine whether or not a crime was committed and to identify a suspect or confirm a suspect's identity. Using the results of the inquiry, a decision is made about whether or not to move forward with a full investigation, formal accusation, and trial.

The process starts when someone files a complaint. A police officer takes down details from the complainant, taking special note of facts that can be verified and people who may be related to the case. Once a complaint has been filed, a determination about whether or not it is valid must be made to rule out situations in which allegations are clearly false. Then, a preliminary investigation can be conducted.

In the investigation, steps are taken to verify information in the complaint, and to expand upon that information. This can involve collecting evidence, interviewing people, and taking other investigative steps. All of this information is pulled together in a report. The report can indicate whether or not the investigator agrees that a crime was committed and it may identify a suspect.

There may be situations in which there is clear evidence of a crime, but no suspect. A person cannot be accused of the crime because no one has been identified, but officers can continue to investigate. They can also keep information about the crime on file in the event that more information comes in at a future date, allowing them to reopen the investigation and potentially to bring someone to trial.

A preliminary investigation can indicate that a crime occurred and that someone is a suspect, but it may also reveal that there is not enough evidence to move forward with a prosecution. In this situation, a prosecutor may recommend waiting on a trial and continuing to investigate the case to see if evidence can be collected to support the case. This decision is made with the understanding that, while the case could be brought to trial, it would be a fruitless endeavor because the outcome of the trial would inevitably be acquittal.

Complainants can check on the status of a investigation. The officer the complainant meets with usually provides contact information to allow him or her to follow up on the complaint.

MyLawQuestions is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Mary McMahon
By Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a MyLawQuestions researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

Discussion Comments
By anon990895 — On May 14, 2015

This is brilliant information, but how can you refer this to an investigation such as the lab. I would really like it if someone can help me.

By anon924732 — On Jan 07, 2014

Thank you very much. This article will surely help me on my report on Monday. Good luck to me. I am a criminologist.

By anon229377 — On Nov 13, 2011

This is a personal experience of a local, a female Ll.B. holder reported a crime to the Philippine National Police (PNP) just last week and reading a published letter by Hustisya at the Bar Ops yesterday piqued a closer look into the conduct of PI as worded in the Rules of Court as amended. It's PI before a complaint, in my case, as of my last visit.

By geronimo8 — On Mar 28, 2011

A preliminary investigation sounds like it could be a slow moving and unbearable time for someone who has had something horrible happen to them or their family. If someone did something bad to me, I would want them taken into custody immediately. I would be worried that they would have the chance to get away during an investigation.

I understand that investigations have to happen to protect innocent people, but it would be very hard to wait.

By claire24 — On Mar 27, 2011

What is the difference between a preliminary investigation and a preliminary hearing? Is the investigation just a gathering of facts, and a hearing more of a formal questioning?

I've heard both of these terms many times before, I just never really understood the difference.

By rosoph — On Mar 26, 2011

This sounds like a good system to me. Can you imagine what it would be like if every complaint that someone made to the police was immediately brought to trial? It would definitely waste a lot of time and money.

It's good that we have preliminary investigations in order to avoid this, and also to protect innocent people. Anyone can make a complaint about someone else. A preliminary investigation makes it possible for people who are completely innocent and falsely accused to avoid having to go through a trial.

Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a...

Learn more
MyLawQuestions, in your inbox

Our latest articles, guides, and more, delivered daily.

MyLawQuestions, in your inbox

Our latest articles, guides, and more, delivered daily.