A Chilean national on parole from the Wyoming State Penitentiary and living in the Denver area has been charged with the rape and beating death of a University of Colorado student a decade ago.

Diego Olmos-Alcalde is being held on $5 million bail on charges of first-degree murder, second-degree kidnapping and first-degree sexual assault in the death of CU senior, 23-year-old Susannah Chase of Stamford, Conn., in December 1997.

Recent forensic science improvements were able to match DNA found on Chase with Alcalde in the national DNA database, according to the Boulder Police Department.

Alcalde, 38, had been released on parole from the Wyoming State Penitentiary in July, said Melinda Brazzale, spokeswoman for the Department of Corrections.

Brazzale didn't know when his DNA sample had been taken, nor where he may have lived in Wyoming, nor what he was doing in the United States, she said.

He had been convicted by a Laramie County District Court on a count of kidnapping and terrorizing a young woman but releasing her without harm in 2000, Brazzale said.

But the first conviction was overturned by the Wyoming Supreme Court in August 2003 because the district court allowed a substitute alternate juror to participate without instructing the reconstituted jury to start its deliberations afresh.

According to the court opinion written by Chief Justice William Hill, Alcalde followed the woman to the parking lot and parked his car so that it blocked her vehicle. He approached her claiming he was lost but when the woman began giving him directions he lunged and pinned her inside the car and began choking her.

The woman was able to sound the car horn twice before Alcalde forced her out of the car and dragged her 15 to 20 feet to a privacy fence. He then abruptly stopped the assault and returned to the apartment parking lot where he was confronted by the victim's brother and sister when they heard the car horn, according to the court opinion.

After the first conviction, Alcalde was given a 12- to 20-year sentence beginning on May 11, 2001.

After the second conviction, Alcalde was given a seven- to 10-year sentence with credit for time served beginning Sept. 24, 2004, Brazzale said.

Because of prison overcrowding, he had been transferred to a prison in Oklahoma, but was returned to the penitentiary in July 2007, she said.

That month, he was paroled to the U.S. Immigration and Customs Enforcement office in Colorado and was allowed to serve at least part of the sentence in Colorado under an interstate compact, Brazzale said.

However, Alcalde did not report to his parole officer in September and a bench warrant was issued for his arrest, she said.

On Saturday, Boulder and Aurora police arrested him at a skateboard park in Aurora for the parole violation, and then served him with the murder warrant on Sunday.

Both the Boulder Police Department and the Chase family expressed their relief.

"As you might imagine our emotions have run the gamut since we first heard of the DNA match with Susannah's case," parents Hal and Julie Chase said in a written statement. "We are delighted that a suspect has been identified and apprehended."

Reach Tom Morton at (307) 266-0592, or at Tom.Morton@trib.com.