LAFAYETTE— Evidence expert Carolyn Booker testified Thursday that DNA collected from Christine Dupuis Wood’s body in July 1989 provided overwhelming proof that Daniel Joseph Harmon had sex with her before she was strangled and shot three times in the head.

In his wheelchair, Harmon, 44, listened to testimony Thursday, the third day of his second-degree murder trial. He was 20 and a neighbor of Wood in the Marigny Circle area of the parish, west of Lafayette, when Wood was killed in her bedroom and her body set on fire.

The case had gone cold until DNA evidence linked Harmon to Wood before she was killed, prosecutors said. Booker, an Acadian Crime Lab forensic scientist, testified Thursday that evidence from the 1989 Wood murder was finally tested in 2006, a result of the Legislature allocating money in 2003 to test DNA from cold cases in Louisiana.

She said the DNA test results were sent to a national database, the Combined DNA Index System, or CODUS, which identified Harmon. He was indicted in 2006.

Harmon’s attorney, Alfred Boustany II, objected to Booker mentioning CODUS. With the jury removed from the courtroom, Boustany told Judge Glennon Everett he objected to any mention of a national database because of what it implied.

Harmon’s name and information appeared during the DNA search for a match because he is a felon and a sex offender. According to the Lafayette Parish Sheriff’s Office, Harmon was convicted of aggravated kidnapping and rape in Tennessee in 1994.

Everett has ruled that mention of all of Harmon’s prior convictions must be kept from the trial and the jury.

“What I’m trying to do is keep the trial as clean as possible,” Everett said. “I’m trying to avoid a potential reversible error if it goes to appeal.”

Everett told Booker to avoid saying the database is a national collection of criminals’ names.

Boustany also questioned the “chain of custody” in the collection of evidence almost 24 years ago, and brought up published studies of “bias” by scientists conducting DNA analysis.

As he did the first day of testimony Wednesday, Boustany objected often as prosecutors Roger Hamilton Jr. and Pat Magee questioned witnesses.

Everett also worried openly in court about media coverage of the case. News outlets have published information about Harmon’s convictions and his failure to register as a sex offender in Lafayette Parish.

Harmon faces life in prison with no parole if convicted of second-degree murder.