NOTE: All of the answers given in this FAQ section by Detective Moore are his opinion based on his knowledge and experience. They are not intended to reflect negatively upon any particular police agency or county attorney’s office.

Crime Scene FAQ’s for writers


Q. How long does it usually take for the police to process a crime scene, days vs weeks?

A. Depending on the severity of the crime and the amount of evidence at a scene, the time will vary greatly.

In death investigations for instance there are four categories:

Natural, Accidental, Suicide and Homicide.

Natural Deaths usually take the shortest length of time. If the person is under a doctor’s care and the doctor is willing to sign the death certificate, these scenes are more complete.

In Arizona a less intrusive investigation is required. An example would be Linda McCartney. She died of cancer in Tucson, AZ. and was under a doctor’s care.

Accidental Deaths may or may not be Homicides. Therefore an extensive investigation would be completed to prove that it was not a Homicide or a Suicide. This can take several hours.

Vehicular Deaths are accidents where, they close down the road and once they prove it was not intentional collect all the evidence and complete diagram measurements this can still take 5 to 6 hours.

Suicides can be tricky. Many times there is no note and the family does not want to admit that they may have been a factor in the person’s death. This investigation must prove that it was not a Homicide, Accidental or Natural and this can take several hours also.

Homicide investigations are investigated the most thoroughly. What the officers and detectives do at crime scenes must be meticulously documented. What they do and don’t do at a crime scene will be under scrutiny when it goes to trial a few years down the road. The homicide crime scene can take from several hours on a small scene with little evidence, or it can take 24 to 36 hours for an involved scene with many types of evidence to be collected.

Q. How long is a crime scene kept intact after the preliminary assessment?

A. Once the scene is assessed and photographed without measurements or placards in place, in other words the scene is photographed how we found it. We determine what evidence there is in the scene; photograph this evidence, collect it, package it and remove it.

Once we have it all we leave a copy of the warrant and a list of the items we took with the responsible party. Then we can release the scene. This is the short version.

Q. If things are missed on the first analysis, are parties able to go back and revisit after a period of time?

A. Once a search warrant is served, the evidence is collected and you release the scene. You return the search warrant to the magistrate that issued it within five days.

If you want to go back to the crime scene you must obtain a second search warrant. The evidence obtained by the second search warrant and the reputation of the detectives working the case will be highly scrutinized by the prosecutor and the defense attorney.

Also this will make it easy for the defense attorney to create doubt with the jury showing how the cops botched the crime scene and had to go back.

Q. Does DNA play a role in every case or has TV overblown its utility? Is it true that the public, particularly juries, have unrealistic expectations because of TV shows like CSI, etc.? Is contamination often an issue? (e.g. Amanda Knox case)

A. DNA and fingerprints are still our best evidence in most cases in order to link suspects to crime scenes, regardless of how T.V. portrays it.

The public and juries do have unrealistic expectations and in Maricopa County the Deputy County Attorney’s do a great job addressing these issues with the juries during a trial.

Contamination was a big issue with the O.J. Simpson case and DNA was very new to law enforcement then. The L.A. Laboratory and the training of their personnel at that time was substandard and under scrutiny.

Over a decade later, police labs and training of lab techs has improved tremendously. Currently, contamination is much less of an issue.

The Amanda Knox case in reference to DNA evidence I think had bloody footprints made in by both Amanda Knox and Victim Meredith Kercher’s containing both women’s DNA. I believe the court rejected the contamination hypotheses in this case.

Other factors that may affect the case are that the Knox case occurred in Perugia, Italy, and was between female roommates. There were three suspects who all knew one another.

Her two male accomplices have been found guilty. Amanda Knox was found guilty in her second murder trial and is awaiting her next appeal results.

Also different cultures and politics can affect the outcome of an investigation. In this case I think they will uphold the verdict and extradite her to Italy to serve her time.

Q. How long does it realistically take to get DNA results and hasn’t the investigation significally progressed by that point?

A. DNA, once collected and sent to the Phoenix Police Lab and is processed in order of priority. Homicide and Sexual Assault cases are “High Priority” and we can expect to have the results within two to three weeks.

Other cases such as Misdemeanor Assaults and Property Crimes: Burglary, Theft and Auto Theft, the DNA will be processed as soon as possible. The DNA results in these cases will take a number of months.

Also as a case progresses there are a lot of loose ends to be tied up by the detectives that the public generally is unaware of.

For instance witnesses and suspects may need to be re-interviewed. Medical records that will show the severity of injuries and the Medical Examiner’s Report that states the manner and cause of death can arrive weeks later. Not to mention obtaining criminal histories of the subjects involved.

When the DNA results come in, it can verify what the scene detectives may have already learned from all the other sources of information. It usually does not send the case in a new direction.

Q. Do defense attorneys and PIs get a chance usually, to visit a crime scene?

A. Crimes scenes are investigated by the police department or sheriff’s office. Upon arrival, officers put up crime scene tape to keep all unauthorized people out of the scene.

Sometimes in high profile cases or exceptionally heinous cases, the Deputy County Attorney will be called to a scene. This on-scene experience may help the prosecutor argue the case better when it goes to court.

Defense attorneys are usually called in on a case after an arrest is made. An arrest may be made at the scene. If this happens the suspect would be brought to police HQ and interviewed. Should the defendant ask for an attorney. The defense attorney would have to go to police HQ to meet with the defendant. Otherwise the attorney would have to see the defendant the next day at the jail. If the defendant has a court appointed attorney it would take longer to see the client. So the defense attorney normally would not have access to the crime scene.

P.I.’s are usually hired by the victim, if alive, or by the victim’s family. This is sometimes long after the police have exhausted all of their leads and are unable to submit the case to the county attorney for prosecution.

So, no, defense attorneys and P.I.’s do not usually get a chance to visit a crime scene.

Q. Which authors do a particularly good job of describing crime scenes? Any who are sloppy, unrealistic?

A. It seems to me that describing a crime scene in a book generally is used by an author to give the reader the required clues to solve the mystery. Because their motivation is not the same as a detective’s they may inadvertently be brief or non-descript.

If you describe every little thing that a detective needs in order to prosecute the case, it may be boring, confusing or meaningless to the reader. I can understand why most of the crime scene information would be omitted from a book by the author.

I find in some crime fiction sometimes the reader is with the suspect while the crime is being committed. Whereas in an older Sherlock Holmes, Miss Marple or Hercule Poirot story, the clues are cleverly laid out for the sleuth to explain.

I can’t really say that crimes scenes written by current authors are described well or just well enough so not to confuse the reader. I don’t think I can single out any particular author that is either particularly good or bad at crime scenes.

Q. What are the biggest mistakes novice authors are making in portraying police work and investigations?

A. I personally don’t like a detective in a crime scene without plastic gloves on their hands and without booties over their shoes.

Biological evidence should be allowed to dry and then be placed in paper envelopes or paper bags. Plastic bags are used a lot on television and in movies. They tend to destroy biological evidence in real life.

Another mistake television shows make is with photographing a crime scene. They don’t always photograph the evidence before it is collected. One show in particular takes pictures of employees caught off guard in the crime scene. This would be embarrassing later in court especially when all of the photos on a photo card are shown to a jury.

Q. What mistakes are made when writers describe what happens in a crime scene?

A. I don’t think of the descriptions of crime scenes by writers as mistakes as much as they are written as a vehicle for the writer to facilitate their story. The writer may only use what they think the reader needs to know about the crime scene in order to solve their crime.

The police detective is looking for the truth. They must collect all the evidence not knowing what exactly will be needed to lead them to that truth.

At the time an item is collected the significance may be unknown. These items should be collected anyway.

A crime writer may have some items collected as a red herring.

Q. How can writers educate themselves about crime scenes?

A. I would start with “Locard’s exchange principle”. This concept is generally understood in the phrase “with contact between two items, there will be an exchange,” Basically the suspect will leave some evidence in the scene for the detective to find. If this evidence is located, documented and collected properly it can be used to successfully link the suspect to scene and possibly prosecute the suspect.

The internet has many crime scene books and articles that can assist a writer, but writers shouldn’t be without real experience. You should think about attending a few court trials where evidence is presented by the prosecution with the detective on the stand. The detective will explain where they found the evidence and how it was collected. You can also see how the prosecution and defense attorneys interact.

Q. Can you recommend specific books, web sites, blogs, Facebook postings, Twitter accounts, and articles that would be informative for writers to learn about crime scenes?

A. The internet is very useful in finding crime scene investigation information. If you read several articles on the internet by reputable detectives, I think you will be able to understand how to properly process a crime scene.

Q. Once writers become educated, how can they keep up with changes in the way crime scenes are processed?

A. Keep up with news. New scientific techniques will be mentioned on television, magazines and in the newspaper before being implemented.

Crime scene investigation procedures are currently pretty sound. If we diligently process crime scenes, good detectives can deduce who had the means, motive and opportunity.
Q. Writers set their scenes in different locations: are there some standard operating procedures for processing crime scenes that would apply in most jurisdictions?

A. Yes, secure the scene larger than what you think you need. Get a search warrant, then thoroughly and methodically document, collect and preserve the evidence. Get it all, get it right and get it the first time regardless of where the crime scene is.

Q. What sneaky deceptive approaches do defense attorneys use to try to discredit your work on crime scenes?

A. The defense attorney phrase I recall is, “If the facts are on your side, pound the facts. If the law is on your side, pound the law. If neither the facts nor the law are on your side, pound the cops.”

If the defense attorneys resort to beating on the police then the evidence and witnesses may be very strong against their client. If the evidence was collected and stored properly, then a defense attorney will either attempt a plea bargain or attack the detective’s service record and job performance. This is why your work ethic and your integrity must always be in check.

Q. Now that entire Genomes can be inexpensively processed in a matter of days, when do you suppose SNPs will be a thing of the past, like RFLP before it? Because Genomes are not as labor intensive as the older technology, do you think jobs will be lost, or do you believe that those people could be used to process the significant backlog of DNA evidence?

A. As I understand it, the genome is the genetic material encoded either in DNA and the restriction fragment length polymorphism or RFLP is used for genotyping single nucleotide polymorphisms or SNPs.                                                                                          Fortunately Genomes, RFLP and SNP’s are in the rat and mouse stages of cloning and are not very well known in the science of law enforcement in the United States. However, when this science catches up with how we currently process DNA, things will change.

In law enforcement we tend to be reactionary in our responses to new technology. I don’t know if DNA will be duplicated to the point that it will no longer be of assistance in identifying individuals or if it will evolve into making identification easier for us.

If biological evidence changes, it has been my experience that law enforcement will make changes to our labs, retain current employees and provide additional training to those employees’ current knowledge base.

Hopefully we can use this technology and science to speed up the backlog of DNA evidence.