Everything about him, from his old clothes to his warm smile, was relaxed - except his eyes, which were as intense as they were back in the day, but focused on a very different target.
The trained killer of enemy soldiers has become a trained rescuer of fellow veterans who are living on the streets as strangers in the country they once risked their lives to serve.
As the lead veteran-outreach worker for the United Emergency Services Fund, Putman has converted his former search-and-destroy skills into a search-and-rescue mission on the Parkway.
Tina Floyd, UESF operations director, said that after the annual single-night count in January, the city's Office of Supportive Housing found 357 homeless veterans among Philadelphia's 5,738 homeless people.
So, even while Putman is smiling and schmoozing with the homeless when they gather for meals on the Parkway or at Broad Street Ministry, on Broad Street near Pine, his somber eyes give him away.
There is no joy in them until he brings a homeless vet off the streets and into a house, a decent job, a reunion with long-lost loved ones.
Putman knows how difficult his mission is because before he became a rescuer of lost souls, he was one himself.
"I had five kills in Panama," Putman said. "I was a trained killer, so after the first one, I had no problem with it. When I came home to Philadelphia, I still carried two 9 mm pistols on me. My body was here, but my mind was still in the military."
One night, Putman was at a crowded club in New Jersey when he felt threatened by another man. "I pulled out my pistol and put three in the ceiling," he said. "The law had been changed to a mandatory five years if you got caught with an unlicensed gun, so I got out of Dodge fast."
When he thought about what had happened, Putman said, "I knew I can't be walking around like this, because I don't have carte blanche no more."
He worked as a limo driver, made good money, looked sharp in nice clothes but was felled by an enemy from his Panama days.
"I fell into drug and alcohol abuse in 1996," Putman said. "I was like the best-dressed addict living in a West Philly crack house. I got a girl pregnant. My daughter was born in April 1998 in the midst of my addiction."
As an infant, long before she knew her father, Putman's daughter saved his life. One day, as he was leaving the crack house to buy drugs, the pay phone on the street rang and he answered it.
"My daughter's mother said, 'You got any money?' " Putman remembered. "I said, 'I got $20 and I'm ready to go cop.' She said the baby needed diapers.
"I thought, 'Do I buy drugs or help my baby?' I said, 'Can you get here in 20 minutes?' Man, she must've been on a jet because she came by and snatched that $20 like a vulture."
Putman knew he had to choose. "I watched my mom raise five children on her own," he said. "I'm a man. I'm supposed to take care of my child."
He went to detox, then to rehab at Gaudenzia. But in the years that followed, jobs came and went, and Putman, living on the thin line between the working poor and the destitute, drifted in and out of homelessness.
He survived in shelters and on the street, stashing clean clothing in hiding spots around the city so that "people never knew I was homeless," he said.
He got a student loan and attended Orleans Technical Institute, in Northeast Philadelphia, studying human services, hoping for a job that would lift him out of poverty.
"I'd ride the El end to end, then ride the Nite Owl bus all night until it was 5 a.m. - time to get ready for school," he said. "School kept me from going off the deep end.
"And I talked to God. I knew I was blocking my blessings. I needed to get out of my own way and let God do his thing."
Whether it was God or serendipity, Putman was walking through Suburban Station last winter when he met an outreach worker for UESF, an agency that traditionally helped poor people pay housing expenses but had just received a million-dollar federal grant to help homeless veterans find housing and jobs.
First, UESF helped Putman. Then, it hired him.
"I'm on the Parkway, I'm in the bushes, I'm under I-95 talking to guys sleeping under the girders," Putman said, as he trained his Marine Corps gaze on the homeless people around him.
"I'm right back with the people I've been sleeping with and eating with," he said happily. "When I was homeless, these people did things for me that Ripley would not believe."
Thanks to his UESF job, Putman lives in a house in North Philly with an extra bedroom for his daughter, now 16, to stay in when she visits. After so many years of living on the edge, Putman has come home.
"There is no place I won't go to help a vet because I am a vet," he said. "My mom, God rest her soul, taught me that if you think you got it bad, just know that somebody's got it worse than you."
Putman's eyes were suddenly moist. "So I give to other people because that's what's in my heart," he said hoarsely. "I'll get my reward when I meet my maker. My God's got my back. I don't worry about me."
On Twitter: @DanGeringer