After pleading guilty to murder and related crimes, Keith Darnel Henry waived the right to have a jury determine his sentence. The trial court found beyond a reasonable doubt that Henry committed the murder while engaged in burglary, armed robbery and kidnapping with bodily injury.1 Based on that finding, the trial court *618sentenced him to death, and Henry appeals.2 Because the trial court erred in allowing the State to make unsupported allegations that Henry posed a future danger, we reverse.
The evidence presented at the bench trial showed that Henry and his wife gained entry into the home of Sheila Dates and her daughter by impersonating FBI agents. Once inside the residence, they bound both women, taped the younger victim’s mouth, and then began questioning Dates regarding the safe at the check cashing business where she worked. Because the procedure for opening the safe proved to be more complicated than anticipated, Henry directed his wife to take Dates to the business while he remained in the residence. He told Dates that he would merely hold her daughter as a hostage. However, Henry admitted in his post-arrest confession that he strangled her to death just 15 minutes after his wife and Dates left the house.
While attempting to open the safe, Dates was told that she was chosen as a victim because she had no husband and was, therefore, “more vulnerable” than her co-worker. Once the safe was opened, she was bound and gagged with a plastic bag. After speaking with her husband by phone, Henry’s wife strangled Dates with a rope. However, she survived the attack, and called for help when she regained consciousness.
After committing the crimes in Georgia, Henry and his wife robbed a bank in Tennessee and then traveled to New Jersey. There, FBI agents discovered the couple in a hotel room. Henry surrendered to the agents, but his wife committed suicide.
When viewed most strongly in support of the death sentence, the evidence was sufficient to authorize the trial court to find that the State proved the existence of statutory aggravating circumstances beyond a reasonable doubt.3
1. Henry makes several challenges to his death sentence. First, he contends that the trial court erred in allowing the State to argue during the sentencing phase that he deserved the death penalty *619because he posed a future danger. Because the State’s argument was not supported by evidence in the record, we agree.
The State argued that Henry deserved the death penalty because he posed a future danger to those in the prison system. This argument was based solely on the crimes Henry committed in this case. The relevant portions of the State’s argument are as follows:
[Henry] has demonstrated completely that he is willing to kill to get what he wants. He’s willing to kill to get what he wants. He tells [a detective] that he wants to die. I don’t know if that’s still his wish or not, but I submit to the Court if that’s still his wish, that he’s willing to kill to do it. He’s willing to kill to get it. If he changes his mind he wants to escape from prison, I submit that he’s willing to kill to do it. And everyone that comes into contact with him is going to be at risk for that. Other inmates, guards, nurses that work the prison system, visitors that come there, anybody that is in his way for him to get what he wants is — is at risk. And I submit to the Court, and I mean this with all due respect, that no matter what this Court decides that you are going to be handing down a death sentence for somebody.
After several objections from Henry’s trial counsel, which were overruled, the State continued:
Right now there is — as an example of my argument for future dangerousness, there is a kid in high school that wants to be a corrections officer, and he has no idea that in a few minutes you are going to decide whether or not [Henry] gets the death penalty for what he did, or you’re going to give him a death sentence. Because sometime in the future he is going to come in contact with [Henry] and he is going to be in the way of what [Henry] wants and he is going to die from it.
An argument that a death sentence is necessary to prevent future dangerous behavior by the defendant in prison must be based on evidence suggesting that the defendant will be dangerous in prison.4 “Arguments addressing [future dangerousness] are not improper if based on evidence adduced at trial.”5 But it is improper for the State to argue that a defendant will kill in prison simply because *620he killed while free.6 The cases cited by the dissent all flow from Ross v. State7 and its predecessors,8 where we made clear that the State must base its arguments on evidence in the record. In this case, there was no evidence presented to justify the State’s argument that sentencing Henry to life without parole would be a death sentence for a future prison guard. There was only the conjecture and opinion of the State. The State’s only justification for this argument was that Henry had committed the murder in this case, and thus it was error for the trial court to allow it.
The dissent argues that this Court cannot review Henry’s enumeration of error because it was not included in his first appellate brief. But Henry properly preserved the error below and included the enumeration in an amended appellate brief filed before we heard oral argument. We have previously held that such enumerations are properly before us, and that our review is not limited to a plain error standard.9 Therefore, Henry need not prove that the improper argument changed the result in his sentencing phase.10 Instead, we ask whether it is highly probable that the trial court’s error did not contribute to the sentence of death.11 Because we cannot reach this conclusion, we must reverse Henry’s sentence.
2. Henry also contends that it is unconstitutional for a trial court, rather than a jury, to impose the death penalty. As a matter of constitutional law, all defendants are “entitled to a jury determination of any fact on which the legislature conditions an increase in their maximum punishment.”12 But the right to have a jury determine whether aggravating circumstances exist so as to authorize a death sentence is subject to the same principles of waiver as apply in any other criminal case.13 Here, Henry waived his right to a jury trial *621as to his sentence and, in accordance with OCGA § 17-10-32, the trial court was authorized to conduct the bench trial to determine whether the death penalty should be imposed.
3. Henry contends that his post-arrest confession was inadmissible at sentencing. After holding a Jackson-Denno hearing, the trial court found that Henry had properly been advised of his Miranda rights,14 and that his confession was knowingly and voluntarily given, and that there was no coercive police activity. We find no error in the trial court’s ruling that this confession was admissible.15
4. Permitting Dates to testify during the sentencing phase regarding the impact on her of her daughter’s murder was not error.16
5. Henry alleges additional errors regarding his death sentence that we need not address because we are reversing that sentence. We do note Henry’s claim the trial court improperly invoked religion before rendering a death sentence, and reiterate that a sentencing body should not resort to religion or any other source except Georgia law when deciding on an appropriate sentence.17
Judgment reversed.
All the Justices concur, except Carley, Thompson and Hines, JJ., who dissent.Henry committed the crimes on August 31,1999. On May 9,2001, the grand jury indicted him for the following offenses: malice murder; ten alternative counts of felony murder; impersonating an officer; possession of a weapon during the commission of a crime; and, possession of a firearm during the commission of a crime. The State filed written notice of intent *618to seek the death penalty on May 14, 2001. Having previously pled not guilty, Henry entered guilty pleas to all charges on January 4, 2002. The trial court conducted the bench trial on sentencing on September 9,2002. The following day, the trial court, treating the felony murder charges as mere surplusage (see Malcolm v. State, 263 Ga. 369, 371-372 (4) (434 SE2d 479) (1993)), sentenced Henry to death for malice murder, and to consecutive five-year prison terms for each of the remaining related charges. Henry filed a motion for new trial on May 29, 2003, which the trial court denied on October 7, 2003. Henry filed a timely notice of appeal on November 5,2003. The case was docketedin this Court on January 15,2004, and oral argument was heard on May 11, 2004.
OCGA§ 17-10-30 (b) (2).
Jackson v. Virginia, 443 U. S. 307 (99 SC 2781, 61 LE2d 560) (1979); OCGA§ 17-10-35 (c) (2).
See Spencer v. State, 260 Ga. 640, 653 (398 SE2d 179) (1990); Ross v. State, 254 Ga. 22, 34 (7) (326 SE2d 194) (1985).
Ross, 254 Ga. at 34 (7).
Pye v. State, 269 Ga. 779, 789-791 (505 SE2d 4) (1998) (Fletcher, P. J., concurring specially).
254 Ga. 22.
Spivey v. State, 253 Ga. 187, 190 (4) (319 SE2d 420) (1984); Horton v. State, 249 Ga. 871, 875 (7) (295 SE2d 281) (1982).
Pittman v. State, 273 Ga. 849, 850 (4) (546 SE2d 277) (2001). Compare Lynd v. State, 262 Ga. 58, 60 (8) (414 SE2d 5) (1992) (plain error standard proper where no objections made at trial and where enumerations raised for the first time over two months after oral argument). The dissent relies on Hittson v. State, 264 Ga. 682, 690-691 (15) (449 SE2d 586) (1994), to support its argument that Henry’s future dangerousness claim must be analyzed under a plain error standard. But the sole case relied on in Hittson was Lynd, which as noted above does not support the dissent’s argument. To the extent that Hittson can be read to have extended our ruling in Lynd to preclude even errors preserved below and raised before oral argument, it is hereby overruled.
Compare Braley v. State, 276 Ga. 47, 54 (572 SE2d 583) (2002); Pye, 269 Ga. at 791.
Cunningham v. State, 248 Ga. 835, 837 (4) (286 SE2d 427) (1982).
Ring v. Arizona, 536 U. S. 584, 589 (122 SC 2428, 153 LE2d 556) (2002).
See Blakely v. Washington, 542 U. S. _ (124 SC 2531, 2541, 159 LE2d 403) (2004); Head v. Hill, 277 Ga. 255, 258 (II) (A) (2) (587 SE2d 613) (2003).
Miranda v. Arizona, 384 U. S. 436 (86 SC 1602, 16 LE2d 694) (1966).
See Lee v. State, 270 Ga. 798, 800 (2) (514 SE2d 1) (1999); OCGA § 24-3-50.
OCGA§ 17-10-1.2 (a) (1). Compare Lucas v. State, 274 Ga. 640, 643 (2) (b) (555 SE2d 440) (2001) (improper to admit victim impact testimony in the guilt-innocence phase).
Carruthers v. State, 272 Ga. 306, 308-311 (2) (528 SE2d 217) (2000).