Regan Connolly, 57, a real estate broker who moved in a year and a half ago, met the couple when Connolly held a party to get to know her new neighbours. "They're nice people," she said Thursday, with a tear running down her cheek.
"She was pregnant at the time," Connolly said. "Both of them were so happy to have a child."
Another neighbour recalled seeing the couple and their young son just last week. They were in the hallway, doing what Manhattan parents do in hallways, teaching him to walk.
But sometime before 3:25 p.m. Wednesday, Wachenheim, a lawyer who was on child-care leave from her job, wrote out a 13-page note. In it, she said she was concerned that her 10-month-old son was not developing as well as he should be, the police said. She also wrote that what she was about to do was "evil."
She then jumped out of her eighth-floor window. She left behind the note. She did not leave behind her son, holding on to him as she crashed to the ground, the crack sounding like a gunshot to people passing by.
Wachenheim, 44, died. But the boy, Keston Aaron Bacharach, apparently cushioned by his mother's body, survived.
"I'm sure you understand, I'm absolutely overwhelmed with grief," her husband, Hal Bacharach, said in a brief telephone conversation from his apartment at the Sutton, the building at 147th Street and Bradhurst Avenue where he had lived with his wife.
"I have my son, who was lucky enough to survive, in my lap," Bacharach said, sounding in shock as he repeated similar words several times. "It's unbelievable. Right now my crying son is in my arms." A child could be heard whimpering as he spoke.
Wachenheim's leap was a jarring twist in the life of a highly educated, socially conscious woman who had been active in a women's group in her synagogue, B'nai Jeshurun on the Upper West Side and, according to her college class notes, had been a coordinator for a Harlem tutoring program.
She was on leave from her $122,800-a-year job as an associate court attorney in the Manhattan State Supreme Court system, court officials said. She had worked for the courts since 1997, doing legal research and helping judges write opinions.
Christian Johnson, a lawyer who lives a few doors down, said he had seen Wachenheim twice last week. There was no indication "that anything was askew in their household," he said. "I was shocked."
The baby seemed normal, he said. Johnson would sometimes ride the train with Bacharach, who never said anything about developmental issues. "Hal never mentioned that to me," Johnson said.
There were clues, however, that the strains and anxieties of motherhood had begun to consume Wachenheim. There was the note she left behind, which was found under a bed, perhaps blown there by wind from the open window, the police said. They did not disclose any more of the note's contents on Thursday.
But Wachenheim's mother-in-law, Barbara Bacharach, said on Thursday that her daughter-in-law had not been her usual self lately. "I know she wasn't herself because I knew her previously," Bacharach said.
Johnson said he had overheard the couple arguing - which he said was very unlike them - about two hours before Wachenheim jumped. He paused in the hallway to make sure it was nothing serious, then moved on when it seemed like a normal marital spat. "He was just asking her why she didn't answer the phone and why wouldn't she pick up the phone," he said. "He just kept asking her and she wouldn't respond."
Asked Thursday if his wife might have had postpartum depression, Bacharach said, "I don't know."
Dr. Catherine Birndorf, a reproductive psychiatrist at Weill Cornell Medical College, said the word "evil" in the note stood out for her, because it raised questions of whether Wachenheim was not so much depressed as delusional. "Usually these intensely lethal acts happen in the context of losing some kind of touch with reality," she said. "What mother in their right mind would kill their kid?"
Postpartum depression does not usually lead to suicide and homicide, she said, unless it is left untreated or progresses to more serious mental illness, like psychosis. She compared it to the case of Andrea Yates, the Texas woman who was found not guilty by reason of insanity of drowning her five children in the bathtub. Yates, who had been struggling with postpartum psychosis, thought that she was a bad mother and that she was protecting her children by killing them, Birndorf said.
About 10 to 20 per cent of new mothers have postpartum depression, according to the state health department, and only 1 or 2 out of 1,000 new mothers have postpartum psychosis. Postpartum psychosis is characterized by delusions, often about the baby, agitation, anger, paranoia, and sometimes commands to harm the infant. It has a 5 per cent suicide rate and a 4 per cent infanticide rate, according to the health department.
Wachenheim was valedictorian at Colonie Central High School, near Albany, and graduated from what is now known as the University at Buffalo, and from Columbia University Law School. In 1993, she travelled to Pakistan to work in a law office specializing in women's rights and worked on subjects like "honour killings" of women suspected of adultery, according to an article at the time in The Times Union of Albany.
Bachrach said he met his wife on a bus to Boston and was smitten by her "innate kindness." They were married in 2009, two years after she bought her apartment at the Sutton for $190,750, according to city records.
The building is in an area that has seen a construction boom and an influx of new residents, many of them affluent professionals, over the last few years.
(Randy Leonard, Sheelagh McNeill and Wendy Ruderman contributed reporting.)