Police procedurals, particularly on CBS, have special rules that real world police might not follow.

Staff need to be directed to perform routine activities:

• We found the murder weapon! Ok, check it for prints.

• We found skin under the fingernails! Ok, check it for DNA.

• We have a suspect! Ok, see if they have a criminal record.

Approaching a suspect:

• To question a suspect at their workplace, two officers will walk shoulder to shoulder rather than approaching a subject from two sides. When they are about 30 feet away from the suspect, they must shout Police/FBI we want to talk to you. A chase ensues.

• To question a suspect at their home, two officers will go to the front door and loudly announce themselves. They will hear some noises inside and shout “He’s going out the back!” and then run to the back of the house. A chase ensues.

• Note: Murderers almost always leave the front door ajar when they leave, allowing warrantless entry to discover the body, or alternately leave part of the body in view of the front windows.

Chases and hunts:

• Chases are inevitable. When two officers are chasing a suspect, one officer will not be able to catch up to them. The other officer will take the long way around and somehow be able to tackle the subject from the side further down.
• When a suspect that has crucial knowledge about the case is being chased, they often run into the street and get hit by a speeding bus.

• When an officer is holding their gun forward while looking for a suspect in an empty building, no matter how careful they are they will be blindsided and tackled by the suspect, with their gun sliding away and requiring hand to hand combat. Often the gun can be reached after the officer has been pulled away from it a couple of times, but if the gun can’t be reached, broken glass works as well.

• When there is a dead body in the middle of a room, the officer will kneel down and start looking at it, and the murderer will then surprise attack them from behind. In such situations, they will often be knocked unconscious.

Rules of evidence are not taught in police academy:

• Officers in police academy are not taught about the necessity for evidence in a criminal trial and need to be schooled by the prosecutor “He is a terrible guy and I just know he did it. Why can’t you stop worrying about your win loss statistics and charge him?” The prosecutor will respond: “The court doesn’t care about your gut feelings, we need evidence to convict him! Bring me some evidence and I will prosecute him to the greatest extent of the law!”

• When the evidence is not sufficient: “We can’t charge them. With what you have, a first year law student could get this case thrown out of court! We need more evidence”

Likeable new officer in peril:

• When a new officer shows up, and some focused time is spent demonstrating how nice of a guy he is and he shows pictures of his wife and children, he will be inevitably killed in the same episode.

Body armor–swat only:

• Swat team members wear body armor and helmets when entering a dangerous building. Show stars do not wear helmets.

Hostage situations and “Standoffs”:

• During a hostage situation, one of the officers will impulsively disarm themselves and approach the hostage while holding their palms forward to show they mean no harm. (Often over the strenuous objections of senior officers or an action-oriented swat team leader.) In such situations, the hostage taker will be talked out of it by the sympathetic. No hostage taker has ever shot anyone after the officer approaches with their palms forward.

• When an officer or officers point their guns at a criminal or criminals who point their own guns at the officers at the same time, there is an implicit understanding that nobody will shoot their weapons unexpectedly until some discussion takes place at gunpoint.
• During shootouts, officers and criminals will courteously take turns shooting, neither shooting at the same time.

Serial killers want everyone to be like them:

• During an interrogation, a sociopathic criminal will torment the officer by claiming “You are no different than me…” A boring philosophical debate ensues.