ATLANTA (AP) — The Georgia father of an accused school shooter could have prevented an attack that left two students and two teachers dead and many others wounded at a school northeast of Atlanta in 2024, a prosecutor said in her closing argument.

“After seeing sign after sign of his son’s deteriorating mental state, his violence, his school shooter obsession, the defendant had sufficient warning that his son was a bomb just waiting to go off," Barrow County Assistant District Attorney Patricia Brooks told jurors. "And instead of disarming him, he gave him the detonator.”

Jimmy Berry, a lawyer for the father, Colin Gray, agreed that what the dad knew ahead of time was of paramount importance in the case.

“That’s real important because that really is the key to this case, is what did he know?,” he said. “Did he know that Colt would do this?"

Gray’s son, Colt Gray, is accused of bringing a rifle his father had given him for Christmas to his school and killing two students and two teachers and wounding many others.

In his closing argument, the defense lawyer held up a picture of Colt Gray, and said “this is the person who went into the high school and shot and killed four people he didn’t even know and injured scores of others.”

“This is the person who needs to be punished," he said. "He made a conscious decision to do this, a secretive decision.”

T he trial began three weeks ago. The jury is expected to begin its deliberations late Monday or early Tuesday.

The trial is one of the latest cases in which parents are being put on trial after their children are accused in fatal shootings, defense lawyers called Colin Gray to the witness stand. He testified Friday that he gave his son a rifle as a Christmas present in hopes of bonding with the boy over hunting and outings at the gun range.

Prosecutors say he should be held accountable for giving his son the weapon despite alleged threats and warning signs that the boy was mentally unstable.

Colt Gray was 14 at the time of the Sept. 4, 2024, shooting at Apalachee High School in Winder, about 50 miles northeast of Atlanta. He faces 55 counts, including murder, in the deaths of four people and 25 counts of aggravated assault.

The father faces 29 counts, including two counts of second-degree murder and two counts of involuntary manslaughter.

In their closing arguments, both sides used images to make their case.

Brooks showed photos of teachers and students closing classroom doors to protect the students and comforting teenagers wounded during 41 seconds of gunfire.

“Those 41 seconds forever altered the lives of the students of Apalachee High School, their parents and everyone in this community," she said.

But the defense lawyer urged jurors to rely on facts, and not emotion in reaching their verdict. He contends that no one could have foreseen the shooting ahead of time.

“Who would be able to foresee that a 14 year old is going to take a rifle, as big as it is, as heavy as it is, and stick it in a book bag, get on a bus, come to school, walk down the hall, go to class, put it down on the floor and not one single person sees it," Berry said. "How foreseeable is that?"

Prosecutors say that's exactly what happened, and they played surveillance video in the trial they say shows Colt Gray getting on a school bus with a backpack that concealed the rifle.

In the video, he is seen entering the school with the backpack. He walks down several hallways past dozens of students and some employees who don’t take notice of the large size of the pack. He then begins classes, and later that morning spends several minutes in a bathroom moments before the shooting.

In dramatic testimony as the trial opened last month, several students testified in court about being shot during their algebra class. They recounted through tears seeing a classmate in a pool of blood, then seeing blood on their own bodies and fearing they might die.

There also has been testimony about what prosecutors describe as a “shrine” to a Florida school shooter that Colt Gray kept on a wall next to his computer at home.

He had an interest in Nikolas Cruz, convicted of the 2018 shooting that left 14 students and three staff members dead at Marjory Stoneman Douglas High School in Parkland, Florida, his mother, Marcee Gray, testified this week.

Marcee Gray testified at Colin Gray's trial that she urged her husband to lock up the guns so that their son could not access them. But in the days before the school shooting, their son kept the gun in his bedroom, witnesses testified at the father’s trial.

The parents were separated for much of the time leading up to the shooting, and Marcee Gray was not charged with any crimes.