Sam Mencimer, 14, stands by the emergency button at the U Street Metro station. After Mencimer complained to Metro that duct tape was covering the button, the agency tweeted to him it had been removed. But he discovered the next day it hadn't. (Kery Murakami/Express)

When Sam Mencimer was just 2, his parents used to take him on Metro, and he’d excitedly watch the trains go by. Over the years, the trains and how they operate turned into a fascination for the self-admitted "train nerd.”

One night in November, for instance, he posted a picture on Twitter of the desk in his room. His lamp has a shade with Metro’s map on it, and his computer screens tracked trains on the Red, Orange, Blue, Green and Yellow lines.

He also seems to know a lot about Metro’s new 7000-series cars. For that, he gets teased by his friends at the BASIS DC charter school, where he is a sophomore. “But it’s good-natured," he said. "They’re all nerds, too.”

As Mencimer, 14, has gotten older and became a regular commuter himself by taking the Green Line from his home near U Street to school by the Archives Metro station, he sometimes has become frustrated. And like a lot of similarly frustrated Metro commuters, he has taken to Twitter “to vent,” he said, complaining one day that the headlight was out on his train, and on another day about a yellow cone on the tracks at U Street.

(Granted, it’s difficult to tell sometimes if he’s acting like adult commuters, or if the adults on Twitter are acting like 14-year-olds.)

But nothing was as frustrating for him as a day last month when Metro gave him a bit of misinformation.

He had just exited the train at U Street after school when he noticed what seemed like a hazard on the escalator to the mezzanine: Duct tape was covering the emergency stop button.

“I don’t want them to not be able to turn off the escalator if my shoe gets caught,” he recalled thinking.

So he’d tweeted to Metro: “Why did you duct tape the emergency stop button cover closed?“

The next day, Metro responded with two tweets through its @Metrorailinfo Twitter account.

"Hi, thanks for calling attention to this. We’ve shared your tweet with our Escalator Maintenance team,” the first said.

Then Metro said, “Hi, the duct tape has been removed from the stop switch. Thank you again for reaching out.”

Mencimer wasn’t buying it. “Okay i will confirm this tomorrow morning and tell you if is still there because judging from past experiences this may or may not be true,” he tweeted back.

He says he didn’t inherit a predilection for skepticism from his parents, both of whom are reporters. He came by it on his own. (His father works for The Washington Post, but had no role in this story, except to give us permission to speak to his son.) He’d once told Metro an escalator at the U Street station wasn’t working. And Metro had tweeted back that the escalator was working.

“It took a week of sending them pictures and videos for them to believe me,” he said.

So the day after being told the tape was gone, he stopped on his way to school to look. There, covering the emergency stop button, was duct tape — just like before.

“Okay you are full of BS, it’s still there,” he tweeted Metro, with another picture of the taped-up emergency button.

“I wondered why,” he said as he stood by that same escalator last week. Why say it was gone when it wasn’t?

Metro spokesman Dan Stessel said he really can’t explain what happened. He said the customer service representative who originally tweeted had been told that an escalator technician had gone to look and found no tape. The technician had even gone to the next stop at Shaw to look for the duct tape, but didn’t see any. “Based on that information, customer service provided a response,” Stessel said.

But if it had been removed, why another tweet days later saying again that it had been removed? Clearly, it had been there all along.

“I have always known to take everything they say with a grain of salt,” Mencimer said.

Got a story about riding Metro or have a question? Send it to kery.murakami@washpost.com or @theDCrider.

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