WICHITA, Kansas -- Since his arrest, Dennis Rader has been corresponding with a family member. The two have exchanged letters. That family member shared one of those letters with us.

The letter from Dennis Rader was written on April 23rd to a family member. What Rader writes about is fascinating, and sometimes, just plain bizarre.

Rader’s letter begins with a thank you to the family member who wrote him. Then, in the second sentence, Rader writes "it hurt to be in jail."

We showed the letter to BTK author, Robert Beattie, who says a grammatical mistake is no surprise.

"Instead of the plural, ’it hurts to be in jail’, ’it hurt to be in jail’. That’s similar to the BTK letters," said Beattie.

The front page of the letter contains a hymn and some mention of his family. On the back, Rader writes more about being incarcerated.

"I spent a least 43 days in or by self under 24 HR guard, and was finally released into housing pod mid April, now I among the "Dirty Dozen" as I have nickname them, including me. We are all Peas in a Pod," wrote Rader.

Criminologist Brian Withrow explains, "The housing units in prisons and jails are often called pods because it’s like a stalk with rooms off to the side of it."

Using the concept of the prison pod, Dennis Rader writes a poem which he titles "Peas in the Pod."

It reads:

The green color Pods at First were long and hollow.

They had grown from Mother Earth, anti-society, into a wild vine.

The vine with Pods, long and curling upward, had many follows;

How each Pod has a unique Pea, that together walks a fine line."

At the end of the poem, Dennis Rader writes his initials, the date, and "Day 54".

"As far as the content of the poem, Peas in the Pod, he is probably trying to make the others feel like he is just one of them, just another con like them to try to get along as opposed to the child killer and torturer that BTK is," said Beattie.

"It was interesting that he took on that term and then started writing a little poem about peas in the pod and the dirty dozen. It indicates to me that he is developing a jail house personality," said Withrow.

Forensic psychiatrist, Brad Grinage, also analyzed the poem.

"It seems to fit in and be in line with him talking about his pod mates, so it’s not just out of the blue for no reason but yet it seems a little strange to be quoting poetry at that particular time," said Grinage.

In his letter, Rader refers to the Sedgwick County Jail as the "System". About his fellow inmates, Rader writes: "Then they start to prowl mid-day up until 12:00 midnight - noisy and hyper."

"It’s got to be incredibly unbearable. I mean, jail at best is not a good place to be -- it’s noisy, it’s loud, it’s transient," said Withrow.

At the end of the letter, Rader writes:

"Tell all and your family hi for me. I think a lot about the family & things missed. The "System" is treating me with respect and care. As the days progress so do my privileges. Hold my love ones, family and other in prayer & thoughts.

Sincerely

Dennis."

The family of Dennis Rader is a constant theme throughout the letter. Tomorrow night we will show you what the alleged BTK killer writes about his wife and children and about the only family member who has come to visit him so far.