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Criminal Investigations



The class is designed to provide the skills, craft, and mindset to become a successful investigator, whether you are in patrol or detectives. Whether it is a homicide or a burglary, your success will be dependent on the steps you take. The ability to talk to victims, identify witnesses, cultivate informants, and interrogate suspects are all necessary in becoming a solid investigator. Knowing what resources are available, drafting search warrants, grand jury subpoenas, and networking with other investigators will also assist in your pursuit of closing out a case. And your job is not complete with the arrest as you must be proficient in report writing, case management, and testimony. How we develop these skills will be discussed through lecture, case study, and class discussion.


Anatomy of an Investigation:

In all investigations there are constants. The reporting party, a victim(s), a scene(s), and an offender(s). How we handle each of these segments will help us in providing the facts we need to start the investigation.

Our Investigators:

Why are some officers better at follow ups then others? We will look at the characteristics that make a good investigator and what it takes to become great.

Crime Scene Preservation:

You are responsible for making sure that your scene is secured. When you get the call, you need to ask the right questions so that your scene is protected until you get there. This may result in you telling a supervisor what it is you need.

Speaking with Victims, Witnesses, and Reporting Parties:

The facts and information we get from victims, witnesses, and reporting parties is critical. We will look to see why it is that these individuals lie, withhold, or mislead us with the information they provide.

Identification of Offenders:

One of our main goals is the identification of an offender(s). The use of show ups, photo arrays, cell phone information, DNA, fingerprints, and interrogation are all tools we use to ID suspects. Search warrant preparation, one party phone conversations, use of informants, and license plate readers, are some of the tools and resources available to us.

Case Management:

Investigations are time consuming and can involve many reports which contain a wealth of information. It is imperative that you can manage your cases in a way, that things are not missed, and critical information is not overlooked. How we manage multiple and major cases is critical for a successful prosecution.


Deputy Chief Denis Linehan is a 27-year law enforcement professional. He spent 25 years with the Nashua Police Department, where he retired as a Deputy Chief. In his career in Nashua, he served several years in the Criminal Investigations Division, serving at every rank through Captain. He currently serves with the Avon, Massachusetts Police Department as Deputy Chief. Deputy Linehan has also previously taught at the New Hampshire Police Standards and Training (Death Investigations) and as an adjunct professor as the Nashua Community College.

Who should attend:

Patrol officers, detectives, and first line supervisors. The information provided is essential in conducting any successful investigation. For first line supervisors who have not been detectives, this information will help in knowing what steps need to be taken before detectives get to the scene.

Course Length:

Criminal Investigations is a two-day course.




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