Fake blood? Latex masks? Watching “Halloween 3” reruns with buttered popcorn popped in trans-fats?

Nah. Let me point you to something that will truly scare you — and it’s not another Herman Cain campaign ad. It was the testimony given in a Montgomery County courtroom last week.

Geniuses working at the Apple store in Bethesda heard bone-chilling screams, grunts and thuds coming from the Lululemon Athletica shop next door to them one night last March. The manager even got another employee to walk over to the wall and listen for a while, just to assure her that, no, she wasn’t just hearing things.

In case you want to think they demurred, red-faced, after realizing what they’d heard was after-hours loveplay or iron-yoga poses, the Apple store manager testified that unnatural human sounds were accompanied by a woman saying: “God help me. Please help me,” and “Talk to me. Don’t do this.”

Still not sure something bizarre is going on?

The Apple store manager, Jana Svrzo, told police: “I heard someone say, ‘Stop, stop, stop.’ And then, ‘Oh God, stop.’ ”

Hmm. What to do when you hear something like this?

If it were a horror movie, the Apple employees, gorgeous and scantily dressed, would follow the scary noises down dark corridors and get killed, too.

If it were the reasonable, civilized society we believe that we occupy, the store employees would call 911 and tell the dispatcher that, maybe they’re being silly, but they are hearing something unusual next door that police might want to check it out.

Instead what they did was nothing. Nothing at all.

The noises on the night of March 11 came from a horrific killing. Svrzo and her co-worker were listening to Jayna Murray, who worked at Lululemon, suffer 322 wounds. The sounds were hammer, knife, wrench, rope and metal bars making contact with a human being.

Wait! There was a security guard at the Apple store that night. What did he do? Pose for an iPod ad, apparently. He was tuned out and heard nothing, ear buds firmly in place.

Nobody did anything. And Jayna Murray died.

The video of a Chinese toddler being hit by two trucks as witnesses did nothing spurred international debate about China’s character. Perhaps it’s a nation whose moral fiber is decaying because capitalism has grabbed hold of its soul, we pontificated.

And yet, here we have a chillingly similar situation in downtown Bethesda, where Brittany Norwood, her attorneys conceded, killed her co-worker at a fancy yoga-wear store in a stunningly brutal way.

I don’t know why Svrzo and Ricardo Rios didn’t call police. Post reporter Michael Rosenwald tried to ask them in an elevator outside the courtroom, but they wouldn’t speak to him.

I can imagine they’ll be forever haunted by those sounds and what they turned out to be.

What really frightens me is that they are not alone in their indifference. Banita Jacks killed her four children and no one seemed to notice. What happened to her neighbors, family and friends, who thought something was wrong, but didn’t seek help?

It’s a long-known effect, commonly known as Genovese Syndrome, after the woman named Kitty Genovese who was stabbed to death outside her apartment in Queens almost exactly 47 years before Murray was killed.

According to accounts at the time, the attack on Genovese lasted about 30 minutes. The victim screamed and begged for help while dozens of witnesses ignored her cries. The attack spawned an entire brand of psychological research that has been validated time and time again.

I spent two decades as a reporter prowling crime scenes where witnesses didn’t see anything, didn’t hear anything and didn’t know anything. The fear and self-preservation instinct that fueled their behavior is almost understandable.

But two people who work at Apple? Not really in mortal danger of retribution in a dark alley.

The commentary on this case went seriously anti-Apple in some instances, with folks vowing to stop shopping at store where iDon’tCare seemed to be the ethos.

Maybe Jayna Murray would still be alive if the same folks Allison Klein wrote about in February — bystanders who chased down two teen muggers after they’d beaten a 59-year-old man in Anne Arundel County — had been shopping in Bethesda that night.

Perhaps we can find those two heroes and have them hold court at the Apple Store Genius Bar, teaching Americans how to dial iGiveadarn on their iPhones.

E-mail me at dvorakp@washpost.com.