If someone has stolen money and you want him held criminally responsible – and hopefully return the money – you normally need to contact the police to file a complaint. This includes filling out a police report, and presenting the evidence that you have. If the stolen money wasn't yours, a less-effective option is to contact the police anonymously. In the U.S. judicial system, a third option is to file a civil suit, which won't result in charges, but may get you your money back.
Filing a Police Complaint
To report a theft that has already happened, the best way to contact the police is to call them using a non-emergency number. In many regions you can simply dial 311 and tell the operator you want to report a theft. In most cases, the police will come to you, although if you are a witness, they may ask that you meet with them at the police station. They will then fill out a report while asking you what you know about the crime. If you have any evidence, like security footage of the crime, or know of other witnesses who saw the crime, let the police know about it.
The police may locate and arrest the suspect immediately. However, it's more likely they will begin their own investigation first, provided they believe they have enough evidence to charge the person. If there is no evidence that the person stole the money, or no one actually saw the crime occur, the police may to close the investigation without making an arrest.
Reporting the Crime Anonymously
If you do not wish to be involved in an investigation, or the subsequent trial, you can report the theft anonymously. Anonymous complaints can alert the police that a crime may have occurred, however they cannot be used to detain or arrest a suspect, or to search his personal property. If the police already know about the crime and have evidence, an anonymous tip may point them towards the right person. This is often the case, for example, when the police have video of an unknown suspect and an anonymous tip points them to the right person.
To contact the police anonymously, you can call their non-emergency number, write a letter, or send an email to them. Some police forces have an anonymous tip line or email system, like crime-stoppers.org used by the Houston Police Department. These anonymous tip services usually guarantee your anonymity, but they are almost always used for crimes the police are already investigating.
Private Complaints or Civil Action
Some jurisdictions give you the ability to bypass the police and file a private criminal complaint directly with the court or district attorney's office. In Philadelphia, for example, you can file a criminal complaint with the Office of the Philadelphia District Attorney for a theft under $2,000. To file a complaint there, you must be a witness or have witnesses of the crime and you must pay a fee, which is $39 at the time of publication.
If you are unable to have a person charged, or even if they are charged, there is no guarantee that your stolen money will be returned to you. In this case, you can sue the thief in a civil suit, rather than a criminal case, to get your money back. If the amount is $5,000 or less, you can usually pursue your case in small claims court. For higher amounts, you should contact a lawyer before pursuing a legal case against the thief.