Planning and Documentation:

Not all investigations are performed by police officers. There are many other agencies and occupations that need to solve problems and conduct inquiries. So it’s important to learn the basics that apply to investigations whether it relates to law enforcement, private investigators or the corporate realm.

“The objective of an investigation is to get the facts so that a resolution of the complaint and situation can be achieved (Thompson, 2007).” Just like Sgt. Joe Friday said on Dragnet, “Just the facts ma-am, just the facts.” The facts are essential to gain a proper solution to the complaint, the crime, or the situation.

Although many cases are resolved out of court, there will be a day that you will be called in to testify or to give a deposition. There, the defense attorneys and others involved in the court proceeding will scrutinize every aspect of your investigation. Is your report accurate? Is it complete? There may be key components of the case that were left out. That could be due to error, or you may have felt that at the time of your investigation, it was unimportant.

They may ask about your case notes and request that you turn them over for review. If your notes are unreadable and make no sense, it will be hard for you to remember what they mean, especially under the pressure of being in a courtroom in front of a judge. Many cases that you work, will not go to court until two or more years later. For this reason, it is crucial to properly and accurately document the entire investigation. If you followed up on a lead that seemed to go nowhere, it is still required that you document that lead in your report. By doing this, it shows that you were not biased, and you covered all the bases.

If you bring criminal or civil charges against the wrong suspect and they end up incarcerated or losing a lawsuit, not only have you negatively affected the person’s life and his or her family, but you bring a reproach on yourself and your department. A faulty investigation could affect someone’s job or their well-being. It could lead to a divorce, a mental breakdown and in some cases, suicide. So the quality of your work is very important and not something that should be taken lightly.
It all boils down to how you document the case. A wise old detective once told me, “If it’s not in the report, then it didn’t happen.”

Initial notification:

We will start with some basics. How did this case come across your desk? How was your agency notified? A police officer could have been flagged down by a witness or a victim. The officer may have seen the crime in progress. Did the call come in from the 911 system? If so, your case will need to include a copy of the 911 recording. In loss prevention or asset protection, the initial notification may have come from an employee, a customer, or a member of management. You may have witnessed the offense yourself. As a private investigator or an attorney, you will most likely be informed by a client.

Review current reports:

Before heading out to begin your investigation, you should review any reports that have already been generated so you can be up to speed on the case. If you have questions about the report or the investigation up to this point, speak to the author of the report for any clarifications. Then document in your report the issues that you may have had and the answers that you derived from those questions.

Review written statements and again plan accordingly:

Examine the victim and witness statements and plan to re-interview them within a few days if necessary. Initially, they may have been traumatized by the ordeal. Due to the stress involved, the witness may have been unable to articulate all the relevant facts from their perspective. If their story changes slightly, do not immediately discredit them. Just document what they say and ask them to clarify the seeming differences. Of course, if their stories are completely off from their original statement, then appropriate follow-up will be expected.

Interviews are a very important part of the investigation. It is recommended that in crucial cases and situations, two interviewers should be utilized. It may be an error in judgment to conduct crucial interviews one-on-one.

During an interview, asking the right questions can be very difficult when also concentrating on the answers, taking notes from the conversation and coming up with the proper follow-up questions. A perfect solution for this is to have two interviewers. More than two could cause the person interviewed to be overwhelmed with intimidation. Assign one interviewer the task of asking the questions and developing a rapport with the subject being questioned, while the other would be in-charge of note-taking.

If there is an important question that interviewer missed, then the note-taker can step in for a moment and ask a follow-up question. The respective roles of the two interviewers should then return back to the original plan. In rare situations, the person interviewed may start directing his or her conversation towards the note-taker instead of the main interviewer. If the subject seems to open up more to the note-taker, the roles may need to be switched. It is important to be flexible and work well together in these circumstances without getting offended. The case should be more important than the ego of the investigator.

“Two interviewers will give you two different perspectives on the situation. Many difficult investigations require tough credibility judgments and it would be valuable to know, for example, that two interviewers have different perspectives on the credibility of a key witness (Thompson, 2007).”

When interviewing, let them tell their story first, then ask them follow-up questions. Follow-up questions can help in various ways. There may have been a misunderstanding on how you worded the question and the witness may have thought you meant something else. You also may have misinterpreted the witnesses’ answer. There may also be a language barrier, cultural differences, or any number of other factors that could affect proper communication. If these issues are present, make sure that every effort is made to clear them up.

Most agencies require the interview to be video and audio recorded, especially in high profile or serious felony cases. A video recording is the best method of properly documenting the conversation. The victim or witness may be crying, showing anger or making furtive movements or gestures. These actions would not be accurately displayed by utilizing a handwritten statement alone.

Crime Scene:

Ensure that the crime scene has been properly documented. As part of a thorough investigation, proper photographs and video must be added to the case file. Many investigators will find that some items will later be discovered in the photos but were not initially found during a search of the scene. Or there may be an object that was involved in the crime, but it was not yet known to the investigators. Sometimes an investigator needs to think like the criminal and try to put himself in the criminal’s shoes. How did he plan the crime? How did he execute the plan? How did he escape? Using this method may help the investigator find evidence that would not have been located otherwise. Be careful when approaching the crime scene, not to disturb any potential evidence. Especially at night, it would be a mistake to accidentally step on a key piece of evidence, such as shoe prints, blood evidence, etc.

After careful interviews are completed, a suspect or a witness may mention, let’s say, that a skillet was used during the crime, but the suspect put it back in the kitchen cabinet. There may not have been any noticeable damage or evidence to link it with the crime at the onset. If this happens and the crime scene has already been released, the investigator must secure a search warrant to re-enter the building and collect the skillet. For this reason, do not release the crime scene too early. The best approach before clearing the crime scene would be to have a meeting with all investigators involved and discuss if there may be any other evidence that needs to be collected.

Not only should the crime scene be properly described in the report, but it should also be documented with photos, videos, case notes, etc. Don’t forget that the victims and suspects are also crime scenes so to speak. Include photos of the victims and the suspects. Collect their clothing, shoes, hair samples, gunshot residue and any other evidence that is needed for the case.

If the case involved Intimate Partner Abuse, then follow-up photos will also be needed to document injuries such as bruising, cuts, scrapes, etc. For example, if a person is punched hard enough in the upper nose area, the initial injuries may not show up on camera as well as they will within the next few days. This kind of trauma will later show up as “raccoon eyes.” The aforementioned is the result of having two black eyes that often include redness and swelling.

Crime scene photography and evidence collection will be covered more in-depth later in this curriculum.


Canvassing involves going door to door and speaking to neighbors surrounding the crime scene area to determine if they were a witness to the violation or anything else suspicious that could help solve the case. Another way to canvass is to set up a perimeter on the roadways within eyesight of the scene and perform a roadblock-type canvass. If the crime occurred on Friday around noon, then the roadblock should be executed during the same time frame, next week and perhaps the week after. Often people will observe suspicious activity but will not initially report it. This type of canvass must be cleared through the local prosecutor’s office and may need a judges’ approval.

If witnesses were located and interviewed, the report should indicate where the canvass was conducted and what was discovered. This suggestion is to ensure that overlapping will not occur and time will not be wasted.

Follow up on all leads, not just the ones that you think are valid. Don’t have preconceived notions or biases. Follow the evidence rather than following your own pathway.

Solvability factors:

Defined: “Factors that logically guide the investigation and are likely to result in case solution (Turner, n.d.).”

For example, a police detective may have ten new cases of someone opening unlocked doors of vehicles over the weekend. Items taken were things like loose change, tablets, purses and other articles left unattended. There were no known witnesses to the crime and no real leads to develop. Cases like these will have to be set aside for more important ones. These cases should be closed out as “lack of leads” to spend more valuable time on to the next. If, at a later date, one of the victims reports that as a result of her purse being stolen, she is now a victim of identity theft. Another possibility is that her stolen cell phone is now pinging at a known location, then there may be leads that will develop from there. In this situation, the new leads can be evaluated for solvability factors. If these factors are met, then the case can be re-opened and investigated more thoroughly.

In Asset Protection, you may find ten empty packages in the men’s restroom. Obviously, there would be no video evidence of this crime, and it would be a waste of time to investigate this case further.

Unless the first responding officer can make a speedy arrest, twelve essential questions need to be answered. These solvability factors are logically based on existing police practices. All agencies may have different capabilities and procedures that result in slightly different solvability factors.

Primary Solvability Factors:

1.   Immediate availability of witness
2.   Names(s) of the suspect
3.   Information about the suspect’s location
4.   Information about the suspect’s description
5.   Information about the suspect’s identification
6.   Information about the suspect’s vehicle and vehicle movement
7.   Information about the traceable property
8.   Information about significant MO (modus operandi)
9.   Information about significant physical evidence
10.  Discovery of useful physical evidence
11.  Judgment by the patrol officer that there is sufficient information to conclude that anyone other than the suspect could not have committed the crime
12.  Judgment by the patrol officer on case disposition. If the officer believes there is enough information available and with a reasonable investment of the investigative effort that the probability of the case solution is high, then the investigation should be continued.

“The utilization of the solvability factors emphasizes the importance of a thorough initial investigation even when it is being turned over for a continuing investigation (Turner, n.d.).” Even if your investigation is not law enforcement related, these same methods can be applied.

Presentation for prosecution:

After your suspect has been correctly identified and your case file is complete, you will need to present it for prosecution. Law enforcement would submit it to the District Attorney’s Office on a state or federal level. If you are a private investigator, this would be reviewed by your agency and then the facts would be presented to your client. As a Loss Prevention Officer, you would present your case to your local police department or to management depending on the type of investigation.

Case clearance codes:

Depending upon your agency’s policy, the case can now be cleared or closed. Examples include:

Cleared – by arrest (suspect was already in custody) Cleared – warrant issued
Cleared – warrant denied (prosecution denied charges)
Cleared – referred to other agency (such as a Family Services, Juvenile Court, etc.) Cleared – unfounded (the case had no merit or was fabricated)
Cleared – exceptional (unusual reason such as death of suspect)
Closed – lack of evidence Closed – lack of leads

A closed case can obviously be reopened as the need arises.

Maintain the case file for future retrieval:

In this 21st century, most records are stored on computers, but evidence, on the other hand, must be kept in an evidence vault for safe keeping. When the case goes to court, this evidence will be needed to help prove the case. Depending upon State or Federal law, the trial evidence will have to be held beyond the “charges filed” stage. It may take years for the case to go to court and then even after a successful conviction, the evidence has to be maintained. An example would be if the suspect appeals the case, it may have to be retired, and the evidence would again have to be made available. Another example would be in the case of a homicide. All homicide case files and evidence are required to be retained indefinitely. There have been many cold cases where the outcomes have been later reversed due to DNA evidence or other factors.


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