The contents didn't weigh much. His grandmother had it shipped to him in Afghanistan. But instinct told him this was not the once-a-month, mass quantity shipment of beef jerky.
Nelson Seo, part of Muchnick's extended "family" in Westport, always sent that.
Muchnick tore open the package and pried off the adhesive tape and bubble wrap to reveal a long, sleek lacrosse stick. It was like getting a piece of home -- his childhood and his days playing varsity lacrosse at Staples High School suddenly dropped in his lap.
"So, he wrote his grandmother a thank-you note," Muchnick's mother, Kate Coakley, recalls. "And he said, `Thank you very much for my stick.' "
Then her voice catches.
It dawns on her that she is still talking about her 23-year-old son in the present tense.
Last Tuesday, two U.S. Marines and a chaplain in full-dress uniform showed up on the doorstep of her Jupiter, Fla., home to deliver the worst news a parent will ever hear.
Her son is dead.
Muchnick was killed along with six other Marines. It didn't happen in combat. Rather, it happened during a live-fire, training drill last Monday night in the Nevada desert. A mortar exploded in a launch tube, and just like that, her boy was gone.
The incident is under investigation by the Navy. So far, there are no answers as to how the mortar shell detonated. Who was where? Or who was doing what?
"If you knew Roger, you'd know he's bright and conscientious," said Seo, a family friend who's known Muchnick since his middle-school lacrosse playing days.
"When he was in Afghanistan, I was sending him pounds of beef jerky every month that he would share with the other Marines at his base," Seo said. "Then I asked him: is there anything, anything at all else that you want that I can send
"He tells me, `Balls. Lacrosse balls. White ones because I'm trying to hook the guys on playing lacrosse one player at a time.' "
So Seo goes shopping. He doesn't ship a handful of lacrosse balls or even a box of them. No, he ships two cases of white Warrior-brand ones. They meet NCAA regulations, weigh about five ounces and have a high bounce and velocity when hurled.
In total, Seo sends Muchnick 240 hard-rubber, high-flying lacrosse balls.
The year is 2011. And outside Muchnick's Afghan base camp, tensions are high. Some of the neighbors beyond the camp wall throw stones. They dump trash outside the base. Some of them spit and curse. They are not the Welcome Wagon for the Marines.
So Muchnick, a lacrosse player known for showing no mercy on the playing field, lets some of his balls go wild from inside the base. With some direction from a fellow Marine high up in a tower who can see over the wall, he focuses -- a little to the right, now more at an angle -- in the direction of one hut.
It's the same hut the Marines know the greatest concentration of stone hurlers come from.
"The hut was a fair distance from the wall," Seo said. "Roger banged up the outside of that hut pretty good. After that," Seo said, "they didn't have a problem with those people in that hut or anyone else. Everyone stopped throwing stones."
To be sure, launching lacrosse balls at outsiders is not a conventional way of resolving conflict. But it was effective.
Although some of his superiors may have mildly admonished Muchnick, his brother leathernecks appreciated his efforts.
And they will never look at a lacrosse stick the same way.