While the security guard might have done the wrong thing by pulling the cord then denying it, it was surely not “inexcusable.” The guy was clearly frazzled after seeing what he saw. Good enough excuse for me.

Of course the thing is, what the emergency brake does is STOP THE TRAIN, so the idea there really is to stop the train from dragging someone along the platform, or maybe to prevent a derailment, althouigh the latetr is really the motorman’s job.

As it is, in this case, pulling the emergency brake didn’t do any harm and could have been of some help.

There is the argument is that this delays medical help – but…

The train was delayed by only one minute in getting into the station. This was not a big delay in getting help – and in fact actually it speeded it up. Till the brake was pulled, the motorman was doing nothing besides moving the train. He was not alerting anybody. Once the train stopped, he called police – and presumably that’s aso about when when paramedics weer called. So they got there faster actually.

The only problem was that Dwight Johnson needed a lot more help than paramedics could give. I don’t know if even a Armed Forces emergency trauma team like what they have in Iraq could have helped him.

Having or not having an an intercom was not an issue in this case, since they were in the same car as the motorman. (A lot of people sometimes gare in the forst car because that might be closest to an exit) Martrinez was banging on the motorman’s cab. That doesn’t mean the motorman didn’t know there was a problem.

A more important question is – couldn’t this trap people in the same car as the murderer? In this case it maybe helped. As soon as the train stopped, the murderer knew he would be caught – but he still had a little hope of escaping identification, so he became less aggressive and not more. He managed to push the knife through the doors and then mingled like he was one of the others. (This part isn’t clear but maybe he was near the victime and people who had run away now came close either to help the victim or to prevent him from escaping.)

Martinez’ motive had been to stop the stabber from leaving at the next stop. The Daily news says taht mayor Bloomberg defended pulling teh emergency brake but what he actually defended was the police keeping the doors closed after the train arrived in the station. Had the not stopped thr tain though the motorman would not have made a call before he pulled into the station – and — I don;’t know – would the motorman have kept the doors closed. The thing is, the motorman knew.

In other circumstances you would not want the doors to stay closed but it is probably standard police procedure now, virtually written in stone, taht the doors shuld always be klept closed while a perpetrator like this is inside because uit wouldn;t be safe for the police (and othwers not currently in danger) to just let him out.

There is no one right course for all situations.

If there had been a working intercom on that car (I don’t think those cars have them, from what I’ve heard) they should have used that to contact the driver and/or conductor. But the brake should not have been pulled. That kind of trapped everyone involved (literally and figuratively) into only a small set of options.