Yes, defense counsel would have access to the evidence the prosecution is using against the defendant, and has powers to get other relevant evidence. And they would make that argument. In a jury trial, web search history would usually be presented by a police investigator. The prosecutor will ask him questions to elicit the picture the prosecution wants to paint, while defense counsel has the opportunity to cross-examine the witness to poke holes in that picture.
Say the investigator testifies that the defendant searched for: "how long does it take for a dog to die in a car?" On cross, defense counsel would definitely point out: "but the defendant didn't search for how long it would take for a baby to die in a car, and he did have a dog he might have been worried about leaving in the car."
Yeah I understand that defense has resources when the argument about intent/state of mind is already made based on search history but I am interested what happens if prosecution searched the computer, haven't find anything and didn't even mention that or flat out refused to seize the computer (because maybe they had reasons to suspect there is nothing to be found).
Can the defense say: "there is nothing suspicious found in the searches so that's evidence the accused didn't plan on killing his child" ?
Minor point but the hearing where this evidence was presented was actually a probable cause hearing, not the trial. Still, the defense can inspect these searches in discovery (fairly sure that's so in Georgia though not a lawyer) and rebut the narrative of the prosecution.
Say the investigator testifies that the defendant searched for: "how long does it take for a dog to die in a car?" On cross, defense counsel would definitely point out: "but the defendant didn't search for how long it would take for a baby to die in a car, and he did have a dog he might have been worried about leaving in the car."