ARAPAHOE COUNTY, Colo. -- A suspect accused of gunning down a couple to stop one man from testifying in a murder trial was found guilty on seven counts, including two counts of first-degree murder.

The jury found Sir Mario Owens, 23, responsible for murdering Javad Marshall-Fields and his fiancee, Vivian Wolfe. The Colorado State University grads were ambushed in their car on June 20, 2005, just days before Marshall-Fields was scheduled to testify in a murder trial.

After two days of full deliberation, the jury found Owens guilty of two counts of first-degree murder after deliberation, one count of conspiracy to commit murder after deliberation, three counts of witness intimidation and one count of accessory to a crime.

The jury was deadlocked on one count of aggravated witness intimidation, so the judge has declared a mistrial in that charge.

The jury will return to court Monday at 10 a.m. for the penalty phase. This same jury will decide if Owens will face execution by lethal injection. The sentencing hearing could take one to two weeks.

Prosecutors decided to pursue the death penalty against Owens, arguing that the murder was a calculated, premeditated plan to silence a witness.

The jury began deliberating Friday afternoon after hearing five weeks of evidence.

Marshall-Fields was to testify against Owens' friend in a separate shooting case. Prosecutors told jurors that Owens was afraid that his role in the murder of Gregory Vann would be uncovered. Even without Marshall-Field's testimony, Owens was eventually convicted of murder and sentenced to life in prison in the Vann case.

Marshall-Fields and Wolfe were driving through an Aurora intersection -- in broad daylight -- when they hit by a hail of bullets. Prosecutors quoted Owens telling a witness that Wolfe died because "she was in the wrong place at the wrong time." Prosecutors argued that Owens lived by the motto of "You snitch, you die."

Owens' defense team said that prosecutors coerced witnesses to shape their testimony to fit the prosecution's case. There were two days of defense testimony but Owens never testified on his own behalf. The defense argued there was no eyewitness to the shooting and the prosecution witnesses can't be trusted. Most have criminal records.

Two of Owens' friends, Robert Ray and Parrish Carter, will also be tried in connection to the murders of Marshall-Fields and Wolfe.

Both Vann and Marshall-Fields were shot at Lowry Park in Aurora on July 4, 2004. Marshall-Fields survived the shooting and vowed to testify against Owens, even though he had been threatened and a $10,000 bounty had been placed on his head, prosecutors said.

Marshall-Fields had told friends less than 24 hours before his death that he feared for his life but that he had to testify because that is what Vann would do for him.