He was a father and grandfather of six, an apartment manager whom residents characterized as both strict and caring, an inventor, businessman and writer who believed in living spiritually and called his aged mother every day.
His killer, by contrast, was a quiet man who seemed lonely and about whom little is known. But a quote beneath his high school yearbook picture would become chillingly prophetic:
"I never like being hit without striking back," Marc Alvin Miller wrote in 1962, quoting a 1903 speech by British politician and imperialist Joseph Chamberlain.
On March 19, Miller, 69, apparently killed Alta Torre Apartments manager Vincent DePaul Collins, 70, in their south Palo Alto complex, shooting him four times in the head and torso, according to the Santa Clara County Coroner's Office. Miller then entered the elevator and turned the semi-automatic handgun on himself.
Palo Alto police have yet to release a motive for the homicide. But one resident told the Weekly the shooting was retaliation: Collins made Miller park his oil-leaking car on the street instead of allowing it in the parking garage.
This week, profiles of the two men — who in some ways could not have been more different — emerged.
A daughter of Collins, who asked not to be named, said her father led a "very colorful and amazing life." He was born in Texas but moved to the Bay Area at age 1. He attended San Jose High School, where he was a basketball star. He attended college at Texas A&M University but soon returned to the Bay Area to work for IBM in sales. An entrepreneur and inventor, he started and owned an aquarium company and later a computer service business, which was successful for many years, she said.
As an inventor, "He was always coming up with ideas," his daughter said, adding that he held patents for a fireplace ashtray and a large-scale water filtration system.
Collins wrote every day, arising at 5 a.m. A spiritual man, he published a book, "New Logic — Living a Life of Harmony," she said.
But the family remembers his compassion and selflessness most.
"When my brother and sister and I and our parents would travel somewhere, like on Thanksgiving, when we would drive through a toll (booth), Dad would pay for the 10 people behind him — and that is who he was. He was always paying it forward, and he taught his kids to do that too. He did it in such beautiful ways," his daughter recalled.
"If you had a problem, he would help you, and you would always leave feeling better. He had a smile and a laugh that would light up a room."
At Christmastime, Collins and his wife would always adopt a needy family. They would bring over presents and food and quietly decorate the person's home and a tree. But he did it without letting the adopted family's children know he had anything to do with it, she said.
"He never wanted the kids to know that he did this for them. It was so important for him to do that for a family and to go in there silently."
She and her father were together for the last time a month ago at her wedding.
"I'm so grateful I was able to be his daughter," she said.
When the family arrived at the housing complex at 3895 Fabian Way earlier this week, residents hugged the family, she said.
"They cried and told us how wonderful my dad is. They were openly sobbing and holding our family."
Collins had managed the 56-unit housing complex for low-income seniors since it opened five years ago.
"Everybody is very upset," Judy Jagerman, an Alta Torre resident, said earlier this week. "It's such a tragedy."
Jagerman recalled what Collins had meant to her. When she faced a crisis and lost her job, Collins told her to "trust in the process." She posted those words in her apartment for encouragement, and she did find a job, she said.
A woman who asked to be identified only as the daughter of tenant Vladmir Divnich said Collins had the tenants and the housing complex at heart.
"He was here before they opened the apartments in 2010, and he interviewed everyone who lived there," she said. "Five years later, it looks like a brand-new place. He was strict, but he didn't come up with the rules."
Collins "was trying to enforce the rules that everyone was supposed to follow. He wanted everyone to live in the best environment. You don't scratch the walls, or you are responsible to fix it. Otherwise, it isn't fair to other people," she said.
But resident Adassa Walker said she'd had a few run-ins with Collins. When her daughter gave her a plant for her birthday, Walker put it on the patio outside her apartment. The pot leaked a little water, leaving a small stain, which made Collins angry, she said.
Collins also made Walker move her car out of the garage and onto the street after it started leaking oil. Her daughter had the car fixed, but recently Collins said it was leaking again. Walker's daughter asked to leave the car in the garage with a pan underneath it until she could afford to get it fixed, but Collins had refused, she said.
That policy might have led to a conflict with Miller, Walker said. Parking on the street is a hardship for older persons. Often, it's difficult to find a parking space and then walk back to the complex, she said. On-street cars also have to be moved every 72 hours.
Miller had spoken with Walker's daughter on a number of occasions.
"He was really upset about his car, and it was going on for a while," Walker said of the disagreement with Collins.
In addition to Collins' role as enforcer of the rules, the 70-year-old might have appeared intimidating to some because he was large, Divnich's daughter said.
"He was a passionate guy with a big presence and a loud voice," she said, adding that both his size and demeanor were tempered by his age.
Miller, on the other hand, was known to be quiet and kept to himself, residents said. He often exchanged pleasantries with others, but few people this week said they really knew him.
Miller left little in terms of a trail, on the Internet or otherwise. He was raised in Longmeadow, Massachusetts, and graduated from Longmeadow High School in 1962, according to his yearbook. His high school portrait shows a slight young man who looked younger than his peers. He smiled in a photograph with the photography club, and he was also a member of the audio-visual aides club and the chess club, and he took part in intramurals.
On the "class caricatures" page, Miller is described: "Always: Democrat; Will be: plumber; Remembered by or for: individualism."
He appears to have lived in several Bay Area cities before landing in Palo Alto, according to online address records, and he may have lived downtown before moving into Alta Torre.
A senior who lives a floor below Miller's fourth-floor apartment and who frequently saw him around the complex described him as "lonely." But though she said Miller lived alone, she didn't think there was anything out of the ordinary about him.
She said she had seen Miller at about 2 p.m. March 19, roughly an hour before police received the 911 call, and nothing seemed amiss. She said she had just walked into the building when she saw Miller walking out of the elevator.
"We just said, 'Hi. How are you?' like neighbors typically do," the woman, who did not want to be identified by name, told the Weekly.
But in a little more than an hour, Miller's life would be over, and Palo Alto police would be investigating their first homicide of the year.
Palo Alto firefighters responded to a 911 call from the complex shortly after 3 p.m. A resident reported that a man in the building's elevator needed medical assistance. They found Miller with a handgun in his lap and an apparent gunshot wound to the head.
About 10 minutes later, police officers who were summoned to the scene found a second body — Collins' — in the manager's office on the first floor.
The woman who dialed 911 told the Weekly that she had been waiting for the elevator with her husband. The woman lives in the building and asked not to be identified by name.
"The elevator opened and I saw someone had collapsed inside," she said. "He was lying on his left side. I saw there was blood near his head."
The shootings triggered a heavy police response to the bustling block, which also includes Loral Space Systems and the Oshman Family Jewish Community Center. For hours after the shootings, the main entrances to Alta Torre and the Jewish Community Center were cordoned off while officers collected evidence.
Yet despite the flurry of activity, police almost immediately determined that there was no danger to the public. At about 4:45 p.m., police said they had recovered the weapon and that they didn't believe a gunman remained at large.
The next day, officials from BRIDGE Housing, which built and manages the property, sent a letter to residents expressing their condolences and concern. They planned to hold a meeting about the tragedy, Jagerman said.
Divnich's daughter said BRIDGE has brought in a temporary manager while looking for a permanent one. Among residents, the first shock has passed, and they are now concerned with the broader issues of their safety, she said.
"They do have concerns that here in Palo Alto something like this could happen. There could have been other people walking around at the time, and who knows what would have happened?"
Alta Torre is a quiet place, she said. The doors are always locked, and tenants have an electronic pass key or must call to get in.
"It's not possible for someone to get into the building otherwise," she said.
Though Collins' and Miller's lives intersected in tragic ways, Collins's daughter said she hasn't encountered Miller's family since arriving at Alta Torre.
"My heart goes out to his family because that is a hard burden to hold," she said of the knowledge that one's family member has killed someone.
"We don't know why this happened. There's nothing that justifies something like this," she said.
Collins is survived by his mother, Margaret Collins, brother Patrick Collins, sister Andrea, son Vincent Collins III (daughter-in-law Connie), daughters Jackie Collins and one who asked not to be identified, and six grandchildren.
A memorial service will be held on Saturday, March 28, at 11 a.m. at the Center for Spiritual Enlightenment in San Jose.
As of Thursday morning, the case was still under investigation, Lt. Zach Perron said. Detectives are not expected to complete the investigation until next week.
• Manager slain at Palo Alto senior complex described as 'strict,' 'kind' (March 24, 2015)
• Victims identified in suspected murder-suicide in Palo Alto (March 21, 2015)
• Police investigate possible murder-suicide in Palo Alto (March 19, 2015)