A Cobb County judge has ruled the trial of an Acworth man accused of killing his new neighbors in 2021 can go forward.

The trial of Matthew Lanz has been delayed for years as attorneys have argued over whether he was competent to stand trial. 

On Nov. 18, 2021, Cherokee County firefighter Timothy Justin Hicks and his wife, Amber Hicks, were found shot to death at their home. The 31-year-olds' toddler was in the house but was not hurt. 

Lanz was arrested in Fulton County a day later, after officials say he stabbed a Sandy Springs officer who was investigating reports of a burglar. Investigators say Lanz attacked one of the officers, stabbing him repeatedly in the back and neck. Officers shot at Lanz and struck him twice.

In the Cobb County case, Lanz is charged with malice murder and 12 other counts, including child cruelty. The indictment accuses him of causing their 2-year-old son physical and mental pain because the child was alone for 12 hours, "unable to feed himself, change his diaper, or get the attention of his parents."

While defense attorneys pointed to a forensic psychologist's preliminary evaluation that showed Lanz was not competent to stand trial, Judge Sonja N. Brown argued in a ruling filed Oct. 24 that interviews showed Lanz "did not exhibit paranoia regarding counsel" and was working with his attorneys.

"Defendant appeared to have the capacity to make rational decisions. There was no evidence that Defendant did not have the ability to recall or relay information," Brown wrote in her ruling. "Defendant has exhibited appropriate courtroom demeanor overall, with a few minor outbursts that did not significantly disrupt the proceedings and are more properly characterized as emotional outbursts rather than mental-health-related outbursts."

A connection with a killing near the Pentagon

Lanz's brother, Austin William Lanz, was identified as the man who fatally stabbed a Pentagon police officer and shot himself with the officer's gun months earlier.

Austin Lanz was arrested in April 2021 in connection with a break-in at a home that shares a back fence with his. The home was sold a few months later to the Hicks family.

The homeowner at the time of the break-in, Phillip Brent, told The Associated Press it was a culmination of a long harassment campaign against Brent and his then-fiancée.

The Associated Press contributed to this report.