Mr. Shields’s father, James Shields Sr., said Ms. Olthof had been planning to take his grandson back to the Netherlands sometime next week. His son had not told him about their heated custody battle.
“He never talked too much,” Mr. Shields said. “He kept everything a secret.”
Nick Stergiou, a freelance film production supervisor, said he knew Mr. Shields as a polite and sociable neighbor who regularly threw parties in the backyard adjoining his. Mr. Stergiou, 31, said he never attended any of the parties, but exchanged friendly greetings with Mr. Shields over the fence.
Mr. Shields was the co-founder of Score Rehabilitation, a Manhattan-based company specializing in at-home care for geriatric patients. The business name appeared on his mailbox, and he appeared to run the company from home, the police said.
His online fund-raiser failed to attract a single donation. In his appeal for funds, he blamed his “spiteful” ex-wife for keeping him apart from his son, saying she had returned to the Netherlands while pregnant because she was unable to find work. He said he traveled back and forth to visit the boy, who he claimed wanted to come to the United States.
Ms. Olthof had objected, he wrote, and would only allow the child to spend two weeks with his father. Mr. Shields said he could not accept that, and the two parents took their fight to court in the Netherlands, where he claimed mothers received preference over fathers.
“The financial stress of this is destroying my current marriage and life …,” he wrote.
“How do I choose,” he continued, between “financially ruining my current relationship vs. giving up the battle for my son?”
Ultimately, he decided not to choose. Instead, the police say, he used a gun to end all their lives.