KTRK-TV aired segments about the letter in newscasts on Thursday and Friday.
Station officials said they received the letter Thursday and verified its authenticity by checking a mail receipt from the Harris County Jail.
Maturino Resendiz, 40, is being held without bond in the Harris County Jail. He is charged with four killings in Texas, two in Illinois and one in Kentucky and is a suspect in two other Texas killings.
Maturino Resendiz gave up in El Paso on July 13th in a surrender brokered by his relatives. He had been termed the "railroad killer" because the victims lived near railroad tracks and were believed to have been killed by someone who rode from place to place on freight trains.
CBS News Correspondent Steve Kathan reports Maturino Resendiz said he turned himself in because he feared his wife would be imprisoned.
"I did not surrender because I was good; the reason was I fear that the U.S.A. was going to put my wife in jail," said the letter, which was in coherent English but marked by errors in grammar and spelling. "And they made many threats to my family, is the reason my family help the USA get me here."
Maturino Resendiz never mentioned anything about the nine killings he is accused of, but did write about his "enemy."
"My wife has a flourescent black light. We turn off all the lights, on the black light. I was so afraid as never before as I look in the mirror, my enemy was me in a different light," he wrote.
"I have been fighting this creature all of my life, and now I know it is me, so I fear, yes I fear and shake," he wrote.
Previously described as religious, Maturino Resendiz described himself in the letter as a "Christian Jew."
"In the Book of Acts, Christians are call a new sect of the Jews and not another religion. My Jesus is a Jew of Jews so I follow Jew and I am a Christian Jew," Maturino Resendiz wrote.
He mentioned the death last month of John F. Kennedy Jr. in a plane crash, President Kennedy and the Bay of Pigs incident with Cuba and the Kennedy family's suffering.
Maturino Resendiz also wrote about how much he loves his dogs back in Mexico.
His attorney, Allen Tanner, said his client sent the letters without his knowledge.
Tanner said he instructed Maturino Resendiz after his arrest not to speak to the media.
Tanner said, "He gets a bunch of letters in jail from media. I told him not to respond,"
Tanner said he reiterated the point to his client after learning of the letter to KTRK.