"He looks so much like his father, it's kind of scary," his mother Kathleen Smith told AFP, as she talked about her unusual decision to have her soldier-husband's baby posthumously, using semen frozen before he was deployed.
"Benton is the child Brian and I could have had. I have part of what Brian and I could have had -- part of my dream was possible even after he died," Smith, 42, said.
"My husband and I had talked about the probability of needing to do in vitro fertilization because I already had a fertility issue. That's why he went to a sperm bank before he went to Iraq," she said.
Smith is not the only US soldier to have semen frozen and held at a sperm bank before deployment to Iraq or Afghanistan.
Many have done so not because they fear they will be killed but because of the risk they would be injured or exposed to chemicals during deployment which could affect their fertility.
"There was a slight increase in military storage in 2003," said Tanya Peebles, spokeswoman for Cryobank, one of the biggest sperm banks in California.
Storage of sperm usually costs 365 dollars a year.
But Cryobank ran a special offer that year, with "semen collection and storage services at a substantially reduced cost, with the first year storage provided free of charge" to military personnel who were about to be deployed to Iraq.
The aim of the promotional offer was "to help ensure the future of their families," according to the advertisement.
However, the widows of soldiers who choose to make the same decision as Kathleen Smith can be counted on the fingers of one hand, the US department of Veterans' Affairs said.
Spokesman Jim Benson said the department knew of only four such cases.
A medical professor at the Uniformed Services University of Health Sciences in Washington, who asked not to be named, agreed women who seek to have their late husband's baby are a rarity, and expressed doubt as to whether it was a good idea.
"It's very uncommon. And I don't think it's a good thing, or that it will become more common," he said.
"The problem is regret -- regret is high for those women," he said. "What happens when she meets someone else?"
"The other question is ethical: the guy hadn't planned to die so he didn't say you could use his sperm," the doctor said.
Smith has no regrets, and Benton has also managed to bring round his grandparents, who were initially against their slain son's widow having his baby after his death.
"His mom was against it. But she's wonderful now. She loves her little boy, her grandson," said Smith.
"Brian and I never discussed whether I would have a child if he died," she added.
"When he died, I was 40 and it's not like I had time to look for another person to be with and to have a child. If I was 10 years younger, it would have been a different situation."
She looks on her son as a blessing and "something good that came out of the war," which she stopped supporting when her husband was killed.
"My opinion about this war has changed, with regard to Brian's death," Smith said. "In the beginning, I was supportive of the war, but at this point I want our guys home."