Imagine this. A swimmer is drowning in a swollen river when a man dives in to save his life. It happened over the weekend in San Marcos, Texas. The drowning man, who said he knew he was dead, survived. But you're not going to believe what happened next.

The hero who risked his own life to save this guy was arrested. Police said he got in the way.

Dave Newman, the hero, who jumped in to save the drowning man and then actually spent a night in jail for saving somebody's life, joined Joe Scarborough on Tuesday to talk about the crazy turn of events.

To read an excerpt of their conversation, continue to the text below. To watch the video of the interview, click on the 'Launch' button to the right.

JOE SCARBOROUGH: First of all, tell us what happened. The guy you rescued said that he was saying to himself as he was going under, "I'm dead. I'm done for." There is no way I am going to survive. You jump in the water, save his life. Tell us about it.

DAVE NEWMAN, SAVED DROWNING MAN'S LIFE: Well, I was in the water when I saw him go under. There was about a four-second span of time when I saw him be carried by the current up under the building.

And, at that time ... I waited for him to come up. And so did some other people. We noticed that he didn't come up. And our level of concern grew. And we made our way over to that area and began to feel back up in that cavity. There is a sort of manmade cave -- I would call it a cavity -- underwater that he was in.

We began to feel back in there. And then some people gathered and brought some ropes and a crab net that we were feeling, probing that area with and then some diving goggles. About the time that the EMS and the police arrived, I had actually brushed up against something in there letting myself down on a rope secured to one of the bars on the wall there at the scene.

I touched something, and then, when I came back up, the police were yelling for everyone out of the water, out of the water, and I knew that I had brushed something up in there. And I thought one more attempt was worth risking going against their wishes, the police.

And when I went down again, a foot appeared amidst the bubbles and so forth. And I thought it was the foot of a dead man. And I grabbed it and pulled and there was no response. I grabbed his shorts, his swimsuit, and pulled myself back out toward the opening of that cavity on the rope.

As I saw the light, I brought him across my body and shoved him up toward the surface. And there was another gentlemen down there, a 19-year-old kid, who was assisting me with this rescue attempt. And he helped the victim there get to an area where the current wasn't so strong and to shallow water, where we could catch our -- he could catch his breath and so forth. I followed.

I was pretty exhausted from the whole maneuver. I needed to stop and rest. I had been swimming and treading water. The man was down under water for 10 to 15 minutes. ...

SCARBOROUGH: Let's get into that, Dave. Let's get into that for a second, because you saved this guy's life. Obviously, you risk your own life to go in there. The police tell you while you are making the rescue to get out.

So, you've got to decide, are you going to obey the cops or are you going to save this guy's life? You decide to save his life. You get him to the shore. And then, when you swim to shore, a cop sticks his hand out. You think he's offering a hand to help you up. What happens next?

NEWMAN: I took a moment or two to catch my breath before I decided to swim across the river to get to the other side, where the police were. There were six or seven of them lined up abreast yelling, hollering, 'Get out of the river, get out of the river now, now."

I paused for a second and I was fairly well exhausted. I needed to catch my breath before I went out across the river and went for another lap there. But, as soon as I could, I headed back out across the river toward the police to comply with their directive at that point. And, as soon as I got to the other side, the officer closest extended his hand to help me out of the water. And I took his hand and he put the cuffs on me and I went to jail.

SCARBOROUGH: That's amazing. Now, I understand -- I understand, Dave, obviously, this guy whose life you saved was shocked you were arrested. The crowd that had gathered there were jeering the police officers, booing them. Talk about how the community has responded, not only to you saving this young man's life, but also to the police throwing you in jail for saving this young man's life.

NEWMAN: Well, I was busy today. It was nonstop interviews from all the different news agencies in our area. I was just amazed when I got out of the water that they had handcuffed me. Also the victim himself, when he was trapped under there -- it was just a quiet day at the river. There were a lot of people down there, of course.

But when he got out, it was the E-mails. The San Marcos Police Department, the university police department at Texas State University, and maybe the SWAT team. I don't know. There was a host of authoritative figures down there.

When the victim, the gentleman, inquired, "What's all this about?" They said "It's because you, you were drowning." This is the response. And he said, "Who is that guy in handcuffs over there? They said, that's the guy who pulled you out."

SCARBOROUGH: That's the guy that saved your life. Exactly.

NEWMAN: That's it.

SCARBOROUGH: Well, listen, Dave, thanks for being here. Man, thanks for being a hero. We greatly appreciate it.

Catch 'Scarborough Country' each weeknight at 10 p.m. ET