NASHVILLE, Tenn. -- The arrest of Jerome Barrett in the Sarah Des Prez case and his accusations of involvement in the Marcia Trimble case have led some to ask: What took so long?

Video: Channel 4 Explores History Of Jerome Barrett, Trimble Case

Barrett was paroled in 2002 after being sent to prison for the 1975 rape of a Belmont student. He was charged in November 2007 with the 1975 slaying of Vanderbilt student Sarah Des Prez.

Trimble, 9, was also found dead in a neighbor’s garage in 1975. Police said evidence led them to believe that she had been sexually assaulted and strangled to death. According to Channel 4 News, officials have also linked Barrett to that slaying scene.

Barrett is a convicted pedophile and rapist. He was on parole for a sex offense sentence when he raped the Belmont student. Since then, some have said he should have been more well-known to police.

So why would it take police 32 years to make the connection and charge him in the Des Prez slaying?

His name wasn't hard to find in the old Nashville Banner archives. There was an envelope, packed with yellowed clippings from the 1970s all about him.

The clippings mentioned the Belmont student, how the school was criticized for a shocking lapse in security, how a housewife was raped and how Barrett was indicted.

“I didn't know anything about him. I don't remember his name. I don’t remember anything at all coming up about him, so, I wouldn't know. I mean, it just never came up. ... It would be something. If we were wrong, we were wrong,” said former Federal Bureau of Investigation agent Richard Knudsen.

“I guess (it’s) what I call tunnel vision,” said retired Metro official Sherman Nickens. “I had an informant tell me that a black Muslim could be involved in this. I do remember going to the mosque on Jefferson Street.”

“They were so locked in on that Jeffery Womack and that kid, that they had to be a known suspect,” said former Detective Ralph Langston. Langston was the first officer to put Barrett in jail in Nashville.

Langston said he prodded colleagues many times through the years to investigate Barrett. But, he said, it was tougher back then.

“Case files were kept by individual detectives except what was turned in to Central Records. So there was actually no central database for us to go to,” he said. “We could not bring up cases the way that they can now.”

There were some patterns in crimes committed in 1975.

The last few paragraphs in a Nashville Banner story suggested a parallel between the rape at Belmont and the slaying at Vanderbilt.

"The attack yesterday is the second in recent weeks involving a student in the university area,” the article said. “Earlier this month, freshman Sally Des Prez was found dead of asphyxia.”

Officials confirm that Barrett's DNA links him to Des Prez, but it took 32 years to make the connection.

As for the Trimble case, another interesting fact can be found in the afternoon paper.

In November of 1975, eight months after Trimble’s slaying, Barrett's rape jury deadlocked.

According to the Nashville Banner, "(The judge) ordered Barrett returned to the Tennessee State Penitentiary where he has more than three years to serve on a Shelby County conviction of carnal knowledge of a female over 12 years of age.”

Though Channel 4 has confirmed there is a DNA match between Barrett and the Trimble slaying scene, he still hasn't been charged.