[Based on Real Experiences] 6 Ways to Investigate Infidelity on Your Own

When you start to suspect that your partner might be cheating, you probably want to uncover the truth. While hiring a professional investigator or detective agency can help you gather evidence of infidelity, taking that step can be daunting. You might think, "What if the investigation doesn't yield any results?" or "I'm just suspicious at this point." So, is it possible to investigate infidelity on your own? Here are six methods, based on real experiences from those who have conducted their own investigations.
1. Check the Contents and History of Their Smartphone or Computer
Most evidence of infidelity can be found in smartphones or computers. For example, if your partner has been exchanging text messages with someone else or has taken photos during their encounters, there's a possibility that they've saved this data.
However, the challenge lies in the "PIN codes" or "password keys" on these devices. If there's a security lock in place, others who don't know the unlock key cannot access the device. Some people who suspected infidelity and tried to investigate on their own have said, "I couldn't unlock the security lock, and after several attempts, I got caught." You might try common number sequences like your partner's birthday or account numbers, but both computers and smartphones can become inoperable after multiple failed attempts. Moreover, if your partner discovers that the device has been locked due to failed attempts, they'll realize that someone tried to unlock it.
Therefore, it's crucial to check under circumstances where you definitely know the password. Additionally, if you succeed in unlocking the device, it's important to search for evidence without leaving any traces.
2. Check Their Wallet
You might find evidence of infidelity in the cash, cards, and receipts in your partner's wallet. Since wallets typically don't have locks, you can check them relatively easily during your partner's bath time or while they're asleep, making this a simple method to do on your own.
A common scenario is finding business cards from restaurants or cards with contact information of employees working there. While they might have obtained these through work-related outings, if you find something suspicious, make a note of the information. You can record it by simply taking a photo of the actual item.
Additionally, receipts that might seem ordinary at first glance could reveal infidelity when you look at the date, contents, and amount. For example, receipts from stores you've never visited or from locations far from your residential area could be considered suspicious. If you find a questionable name, it's recommended to search it online and use that information for further investigation.
One real-life experience involves someone who detected signs of infidelity by finding contraceptives in their partner's wallet despite trying for a baby. It might be a misunderstanding, but if you're already suspecting infidelity, it's better to uncover the truth.
3. Check Credit Card Statements
Similar to checking the wallet, you can examine credit card statements to see what your partner has been spending money on. Statements include "purchase date," "amount," and "details" (such as lodging fees or shopping), which can make suspicious activities clear—for instance, "They made purchases on a day they were supposed to be at work."
However, with the rise of paperless systems, statements are often uploaded online and checked via computer or smartphone. To view statements under your partner's name online, you'll need the credit card company's ID and password.
Be cautious, though; viewing statements without the cardholder's permission can be illegal. If an envelope from the credit card company is marked "Confidential," it means it shouldn't be opened by anyone other than the intended recipient, and opening it could be considered illegal. Similarly, obtaining and using someone's ID and password without permission is also illegal, so please be careful.
4. Install a GPS Device
GPS is a system that can determine the location of installed devices or equipment. By using it, you can track the movements of a cheating partner by installing it in their car or downloading an app to their smartphone. There are various GPS-enabled products available, such as GPS patches for theft or loss prevention that can be purchased online. However, while installing GPS on your own car or your own belongings isn't illegal, placing it on your partner's property without consent may violate criminal laws.
5. Check the Car's Mileage
The mileage on a personal car is designed so that it cannot be tampered with manually. Therefore, if your partner might be using the car for infidelity, regularly checking the mileage can help reveal the truth. Similarly, you should also check the car's navigation history. They might be searching for leisure facilities or tourist spots even though they're supposed to be on a business trip.
This check needs to be done frequently to be meaningful, and if they're not using the car during their infidelity, you won't find anything suspicious. However, since it's a simple method with no legal issues, it might be worth checking at least once.
6. Confirm Their Use of Social Media
Lastly, confirm whether they are using social media. Even if they've told you, "I don't use social media," there's a possibility they've registered solely to communicate with someone else. Most social media platforms allow user searches, so you can check if your partner is registered.
If you find their social media account, you can look for interactions and record any potential evidence by taking photos or screenshots. However, as you'll find when you try to investigate on your own, it's challenging to find the relevant account through user searches. Even if you do find it, they might be using "direct messaging" features that only the two of them can access.
Conclusion
Many people who suspect their partner of infidelity want to investigate on their own without incurring costs. However, some methods may carry legal risks, and there's a high possibility that you won't be able to obtain conclusive evidence on your own. If you wish to submit evidence of infidelity for use in court or settlement negotiations, it's advisable to hire a professional detective or investigation agency to obtain accurate evidence and documentation.
Disclaimer
This column is a translation of content originally written in Japanese. Please note that the legal information and references mentioned here pertain specifically to the laws and regulations of Japan. If you are seeking legal advice or information relevant to your country, we recommend consulting a professional familiar with your local laws.