A judge will allow a DNA expert to testify in the murder trial of a man charged in the death of his estranged wife.

Stephen Vargas, 40, is accused of the Dec. 28 bludgeoning death of 27-year-old Rebecca Weaver. His trial is set to begin Monday in 2nd District Court.During a motion hearing Friday, Judge Michael Lyon refused defense attorney Martin Gravis' request to prohibit the state's DNA expert from testifying at the trial.

Gravis argued that because prosecutors had not given defense attorneys information about the laboratory where the DNA testing was done, the testimony should not be allowed.

But Lyon ruled that prosecutors did not act in "bad faith," a condition that has to be met before a judge can suppress testimony.

The DNA testing was done by a private Richmond, Calif., lab because at the time of the murder, the state crime lab did not perform tests necessary for small samples.

The defense plans to argue that the lab technician who did the DNA testing is not an expert, and that the lab results based on testing procedures the technician used could not produce a match because the sample was too small.

Gravis said the DNA evidence is a speck of blood found in the floor of Weaver's car.

Prosecutor Sandy Sjogren told the judge the information Gravis wanted is not relevant to the Vargas case and is merely a "fishing expedition" to discredit the lab. She said the lab is compiling the information requested, but she could not guarantee it would be ready for the defense before the trial.

Lyon ruled that the information Gravis had requested was not relevant to whether the expert was qualified, meaning Sjogren does not have to give Gravis that information.

Lyon also scolded Gravis for not turning over a synopsis of the expected testimony of the defense's DNA expert.

Prosecutors allege Vargas' obsessive relationship with his wife led to her death. Weaver, who police said was leaving Vargas, was found outside an Ogden apartment she was planning to rent.

She died from six or seven blows to the back and top of her skull.