The police not only have a secret jail in Chicago known as "Homan Square" where they can torture the truth out of you, but they, and indeed most police agencies possess this, it is called the Reid Technique. If you follow the link you will read an interesting paper on the Reid Technique.

It seems that once apprehended, rightly or wrongly, it makes no difference, we lose the ability to ask for an attorney and our body undergoes changes placing an air intake valve right where our anus used to be so that we can talk to the police without taking a breath. If you are a suspect, and if the police haven't caught their man, then everyone is a suspect, don't talk to the police without an attorney present. And the attorney, unless he has a reason, will probable either not issue a statement or do so in writing. Everything you say will be looked at to see if it implicates your involvement in the crime no matter how circumspect. i.e. Were you in the geographical region when the crime occurred, yup, well, confess so we can move on to the next case.

The men in blue are under paid, under appreciated, and under supervised. There is no reason not to have body cameras on each of them. Where the Reid Technique is concerned the interview takes place in a room that is either small or made to look that way. All I have seen have a recording device hidden in the room or out in the open.

There are nine steps to this approach. That being said, I have never seen an investigator worth his salt that didn't also look for innocence, but to see how institutionally biased this "Technique" is  you only have to look at the first step of the 9 step process

1.  Step One of the interrogation is called the direct positive confrontation. This is a procedure to advise the suspect that the investigation clearly indicates that he is responsible for the commission of a crime. You should know that the Supreme Court has endorsed this kind of trickery, and much much more. Think about that. (Consider a forest fire where the fire was started by a cigarette being thrown from a window. Might have been you, you smoke after all, and you were on the balcony earlier.....) This parenthetical was taken directly from the Reid Technique article linked above.
2. Step Two of the process is theme development. This sounds relatively harmless, but it is insidious in it's effect. Theme development is a method of lying whereby you reinforce the justifications in the suspect that support him having taken the action and committed the crime. Heck, I watched a good friend of mine get his client fined $500.00 for killing her husband. He used the "he deserved killing defense" The police will reinforce the concept that you removed a blight on society if it serves the purpose of the case. Obviously this step is as adaptable as it has to be. It is where the state capitalizes off the human frailties of wanting to help to draw you closer to the exalted role of "person of interest" or better yet (for them) primary suspect.
3. The following is taken directly from the article The Reid Technique of Interrogation by Brian C. Jayne and Joseph P. Buckley. --"Steps Three and Four both address statements the suspect makes during theme development.  Most guilty suspects and all innocent ones will offer denials during theme development. An important principle with respect to denials is that the more often a suspect denies involvement in an offense, the more difficult it is for that person to tell the truth.  If a suspect is permitted to voice too many denials he becomes committed to that position and no amount of persuasion will allow him to save enough face to tell the truth.  For this reason, the investigator will discourage the suspect from offering weak denials." Three fourths of the technique so far is focused solely on "Theme Development".
4. Step Five is designed to get the person being interviewed to relax somewhat. His attention is directed to the Theme. If you will recall the "Theme" is anything that makes the suspect feel justified or not to blame in the crime as it occurred. 
5. Step Six comes from a very old trick indeed. Have you ever heard an old attorney ask you "Do you still beat your wife." It is an example of an impermissible question that naturally assumes the answer so that there is no right way to answer it. Indeed the solution is to NOT answer the question. Well, here at step six the officer who has moved in closer to his suspect, who has already developed a self reinforcing, but otherwise meaningless, justification/excuse. He has already in step five tried to get him to lower his guard which works best if your innocent and know you didn't commit the crime. What did you have to be afraid of anyway. Protect and serve, you will be thinking that your on the same side, but you are not.
6. Step Seven is called presenting an alternative question. "Did you do it because you had to feed your family or were you really trying to hurt those people?" Hopefully you can see the false logic and manipulation happening in this step. The kicker is that this step is prohibited from containing any real substance in the way of an agreement as to consequences if you confess. It relies wholly trickery and manipulation along with a fine understanding of human nature.
7. Step Eight Secure the oral confession   
8. Step Nine Paper it up. Get a signed confession if you haven't already recorded it which is what everyone does. They then produce a transcript if the session was helpful to them.

So, the police have a reason to like you. If it is a good investigator he will have you nailed nine ways to Sunday. If the investigator is lazy then he will solely use this technique in an attempt to wrap it up quick. The good ones always have a series of questions that they know the answer to, or hopefully they do. And they use these questions to develop responses from you and gauge their truthfulness.  Don't lie to the police. Don't say anything other than you want your phone call and you will not speak about this or any other matter without your attorney present.