ST. FRANCISVILLE — Jurors in the David Brown first-degree murder trial are expected to decide Friday whether or not the Angola inmate should die by lethal injection for the 1999 slaying of an Louisiana State Penitentiary security officer.

The eight women and four men on the jury, chosen last week in St. Tammany Parish, deliberated about an hour and 45 minutes Thursday before returning a unanimous guilty verdict against Brown in the beating and stabbing death of Capt. David C. Knapps, 49, during an escape attempt at Angola’s Camp D.

A unanimous verdict also is required in the separate penalty phase of the trial in order to sentence Brown to death. Jurors could vote unanimously for a life sentence, but a split verdict also would result in an automatic life sentence.

Brown, 38, is serving a life sentence at Angola for second-degree murder in the May 1992 shooting death of a Marrero man, Harvey Reese.

He is the third of the so-called Angola 5 inmates to be tried in the slaying. Prosecutors secured the death penalty against Jeffrey Cameron Clark, 50, but another jury could not agree on the death penalty for Robert Carley, 48, who was then sentenced to another life term.

In closing arguments Thursday, prosecutor Mike Futrell told the jurors the defense’s own expert witness, Larry Renner, of Santa Fe, N.M., agreed Brown was directly involved in murdering Knapps.

Renner also agreed with state witnesses’ conclusions about blood evidence found on Brown’s clothing, Futrell said.

Questions raised by the defense about irregularities in collecting and handling evidence and documenting the crime scene are “smoke and mirrors,” the prosecutor said.

“The defense is all about deflecting attention away from David Brown, but they’re stuck with the facts of this case,” Futrell said, including Brown’s statement that he held Knapps down while other defendants beat and stabbed the victim.

“Even if all he did was hold him down, he’s guilty of first-degree murder,” Futrell argued.

Defense attorney Mark Marinoff asserted that Brown had no intent to kill Knapps because the would-be escapees needed to get clean uniforms from security officers to walk out of the prison camp.

“There was no thought process where a guard’s bloody uniform could be of any use,” Marinoff said.

“You cannot convict him for first-degree murder without specific intent (to kill or cause great bodily harm). His statement implicates him for second-degree murder,” Marinoff said.

Lead prosecutor Tommy Block told jurors in his rebuttal that Marinoff’s arguments illustrate the “reason why the law says that what lawyers say is not evidence.”

Brown’s role in the escape plan was tactically sound, Block said.

“He was the muscle. He was holding him down,” Block said.