Based on my 22+ years in the system, a few points:
1. Interrogations rarely lead to confessions. I know, you see the big deal confessions on the news. But in my experience, the Perry Mason moment rarely comes. An interrogation does two things. First, it gets information that investigators can use to either corroborate the evidence, or contradict it. If it contradicts the evidence, you have to consider the validity of the evidence, or if the evidence is solid, use the false statement against the subject, either in a subsequent interrogation or in court. Second, and more useful to me as a prosecutor, it locks the defendant into a version of the story. If you have a version from the interrogation, and the evidence establishes that the story is false, you have pinned the defendant in a corner, and they cannot change stories. If they do, you cross examine based on the interrogation, and lead up to the always fun questions "were you lying then, or are you lying now?"
2. Most criminals are dumb. Smart criminals are few and far between, and they rarely get caught unless they do something dumb along the way. These days, technology catches up to far more criminals than interrogations ever did. People love to put photos on line. Had a case a couple of months ago. House for sale, sitting vacant. Break in, thousands of dollars of damage. Idiot teens had a drunken orgy in the home after kicking in the back door. And they posted photo Instagram and Facebook of themselves in the house. Most notably, photos of themselves doing the damage to the house. Security cameras at banks and stores have really helped with check fraud, as you can see who presented the check. Similar with stolen credit cards. And a big one these days are recorded jail calls. People being held in lieu of bond seem to make a lot of calls, and they tend to talk about the crime. One I recall was a guy who unintentionally killed two people by overdosing them with heroin. He shot them up at their request. Charged with involuntary manslaughter. I had to put the syringe in his hand. He called his girlfriend, and during the call, he said "baby, you know I'm the doctor." She asked what that meant, and he explained how he bought the heroin, prepped it, and injected both guys. That was the nail in the coffin on the cases.
3. A final point. Most jurors are people who have watched hundreds of hours of television. They come in with certain expectations as to how the investigation worked. Thanks to CSI shows, they often expect a fingerprint, or God forbid they expect DNA in every case. If the case involves an interrogation, they expect that it was something like they've seen on NYPD Blue or Hawaii 5-O, where a suspect ends up getting smacked around after being put in a windowless room for hours, deprived of food, water, and screamed at in the process. I can't tell you how many jurors I spoke with after trials who expressed surprise if an interrogation took place at the suspect's home, or in a park, or if the officer spoke in a friendly tone with the defendant. Hollywood (shocked face) poisoned the public minds about how the criminal justice system works, just as they have about gun owners.
