A man facing a possible death sentence if convicted in the 2008 slaying of his ex-girlfriend and her 3-year-old son at a BREC park near Zachary rejected an offer to plead guilty in exchange for a life prison term.

“We’re in complete agreement — me and my attorneys,’’ Dominique Dantoni Smith, 31, of Wilson, told state District Judge Tony Marabella on Thursday, shortly after one of Smith’s lawyers told the judge the offer was declined because Smith is “innocent.’’

Prosecutor Darwin Miller, who noted that the offer was made at the request of the victims’ family, said the offer is now off the table and will not be revisited.

Richard Goorley, one of Smith’s court-appointed attorneys, said Smith wants to go to trial.

“We’ll gladly litigate that,’’ Miller replied.

Smith is scheduled to return to court Oct. 20, when Marabella said potential trial dates will be explored.

Smith’s girlfriend, Trendall Lashel Matthews, accepted the state’s offer June 20 and pleaded guilty to two counts of first-degree murder and two counts of attempted first-degree murder in return for a life sentence.

She agreed to testify against Smith.

Prosecutors were seeking the death penalty against Matthews, 25, of Jackson, as well.

Smith is charged with two counts of first-degree murder in the killing of Jessica Johnson Palmer, 23, of Baker, and Juan Palmer Jr., 3, at Doyle’s Bayou Park on Pride-Port Hudson Road on May 4, 2008.

Smith and Palmer were once romantically involved and had a child together. Matthews and Palmer are cousins.

Smith also is charged with the attempted first-degree murder of two of Palmer’s children: Lindsay Paige Johnson, who was 4 years old at the time, and Robbyn Palmer, who was 6 months old.

Lindsay Johnson, whose throat was slit, and Robbyn Palmer were left overnight in the park for dead.

When Matthews pleaded guilty, Miller said in court then that Smith and Matthews met Palmer and her children at the park, and that Smith and Palmer were talking about paternity in a remote and isolated area of the park when Matthews heard screams.

Miller said an altercation and argument then erupted involving the three adults, and Smith knocked Palmer to the ground and eventually cut her throat.

While Palmer was on the ground, the prosecutor said, Matthews “placed her feet on Jessica Johnson Palmer to hold her down’’ while Smith continued to cut her.

Matthews also confessed that she was holding Juan Palmer Jr. and Lindsay Johnson when Smith cut them, Miller said, adding that Juan Palmer Jr.’s body was burned.

The prosecutor said a baseball bat also was used in the attacks, although Matthews denied that claim.

East Baton Rouge Parish sheriff’s detectives have testified previously that Smith implicated himself and Matthews in the attacks.

Smith told detectives he and Matthews bought a baseball bat and lighter fluid before meeting Palmer and her children at the park, according to an arrest affidavit.

Smith said he and Palmer went for a walk, during which he grabbed her hands while Matthews attacked her, the affidavit says.

Smith said he and Matthews purchased new clothes at an area store and used the lighter fluid to burn the clothes they were wearing, the affidavit states.