The world is a dangerous place, not because of those who do evil, but because of those who look on and do nothing.

Albert Einstein is quoted to have said that decades before a man killed his ex-girlfriend in an Edmonton apartment building this week while people stood by and did nothing.

It was last Monday just after midnight. She screamed loudly enough that one of her neighbours crept down the hall to check it out. No one called police.

Her screams didn't go unheard - they just went unanswered.

Thirty-eight-year-old Nadine Skow, brutally stabbed, then lay dead for a day and a half. Police found her after co-workers phoned them Tuesday morning, worried she didn't show up for work.

But Skow's screams were not the only calls for help that people in her three-storey-walk-up ignored that night.

A second woman was attacked in the same building, minutes earlier.

Brooke Miles cried out after she awoke to find a strange man in her apartment. He had walked through her front door, which didn't lock properly because it was damaged. She grabbed an umbrella, fought him off, then ran out the door and started screaming.

Police say her attacker is the same person who killed Skow, and he may have gone into Miles's apartment by mistake.

"If he got a chance to get his hands on my mouth I probably would have been hurt, I'm sure of it," Miles said two days later, wiping away tears.

She escaped, but her neighbour didn't.

And now Miles, the people who live in the 22 units inside that building, and the rest of us are left to wonder — what if?

What if someone had called police sooner?

"You know, there's a possibility if police were called this might not have happened," said Staff Sgt. Bill Clark at a news conference this week.

Staff Sgt. Bill Clark stands outside the murder scene. (CBC) Seconds count when a person's life is in danger. If someone had called 911 after hearing Skow or Miles scream, it's possible this would have ended differently.

It's also possible it would have ended the same.

Jasmine Chaos believes a phone call would have changed nothing.

She used to live a couple of blocks away from the building where Skow was killed. Chaos said she called police more than 10 times about prostitutes, drug dealers and gun violence. But it often took hours for officers to get there.

One night she heard two men fighting in the apartment next to her. They were known drug dealers. They were yelling and threatening to shoot each other. A family with young children lived across the hall.

She phoned police at 2 a.m. She says they showed up to investigate at 7 a.m. By that time, the men who were yelling were gone.

"When you get let down that many times, you stop putting your faith into the people who are supposed to protect you," she said.

Chaos stopped calling police. And decided to move elsewhere.

"Luckily I had the means to leave that neighbourhood. But not everybody does," she said.

Enter Skow's apartment complex near the corner of 104th Street and 106th Avenue, and it's clear the residents of that building likely only live there because they have to: dirt and black scuff marks trail up and down the once-white hallways.

Five days after the murder, yellow police tape still props open the stairwell door on the third floor. A window on the main floor is blacked out with cardboard. There are stains on the carpet. An apartment door on the third floor has a section sawed out of it.

Several people buzz to let us in the building, but don't answer calls to come out of their apartments to talk. They're either indifferent or afraid.

Research tells us that on that day, as well as on the night of the murder, it was most likely the latter.

What if people are hard-wired not to help?

"People get almost trapped in their own inability to act," said Wade King, adviser to the University of Alberta's office of safe disclosure and human rights.

He trains and gives presentations on why people choose to do nothing when they see or hear something wrong – and how to prevent that.

Research shows people in a group are less likely to jump in than when they are alone.

It's called the bystander effect. The concept was popularized in the 1960s after the high-profile murder of 28-year-old Kitty Genovese in the U.S. She screamed for help several times during a stabbing in a well-populated area of New York City. No one came to her aid.

"If you're a single person who sees a pedestrian vehicle accident, the [bystander effect] theory tells us you will act. Because you're the only person present, you will interpret it as an emergency and you will feel that it's your responsibility," King said.

"But for every extra individual who is at the scene of an accident, every single person at a subconscious level finds a way to talk themselves out of acting."

And it's more common than you might think.

Crowds have ignored – or stood by and watched or video-taped – some high-profile attacks and shootings in many Canadian cities, including Vancouver, Toronto, Montreal and Edmonton in the past.

King said willingness to help is shaped by cultural background, social standing, previous experiences and whether someone feels stepping in would be a risk to their safety.

"I think it's very easy to sit back and think 'I would have done something,' or 'I can't believe those people didn't do something, ' " King said.

"But there are a myriad of factors...that really do tie people's hands and make them unable to do the things that we think should be easy to do."

What if there are dying women screaming all around us?

Brooke Miles is a survivor of an abusive relationship.

This memorial marks the spot where 29-year-old Claudia Mary Iron-Howard's body was found. She died from a stab wound to the chest in early June, one street over from the apartment building where Nadine Skow was killed. (Rick Bremness/CBC) She said she once landed in hospital for weeks because of it. And the attack in her apartment on the night of the murder shook those memories, hard.

"I kind of go into shock. So I have a really hard time remembering," she said, a tremor cracking her voice. "It's scary."

Miles had been living for weeks without a working lock on her door. If she couldn't afford to fix that, one wonders what else she couldn't afford.

She and her neighbours live in an area where there were two murders and a suspicious death in a seven-block radius since June. It's a neighbourhood where low-income families live alongside drug dealers, prostitutes and pimps, with a rate of crime that police admit is difficult to keep up with.

"They're down here all the time," Clark said of the many beat cops that roam here each day.

"But without hundreds of officers you can't have one on every corner for every little incident. Sometimes people get a little complacent. Some think they don't want to bother us. But that's what we're here for."

Blame the bystander.

For some, it's easier than asking uncomfortable questions.

Would you call police if you heard screams in the night and worried the subject of your call might find out and target you or your children next?

Do you speak up, even when the stakes are much lower?

What do you do when you see a bully at work, a stranger berating another stranger on the bus or a possible crime in progress in broad daylight?

According to King, individuals will only be encouraged to "upstand" – the opposite of "bystanding" – if there is more widespread cultural support to do so.

"One of the ways to fight against it…is for someone to take an overt stand against the behaviour," he said.

Perhaps more evil than standing by and doing nothing, is the failure to figure out why it keeps happening — and prevent it.

marion.warnica@cbc.ca

@warnicam