There have been more than 70 incidents since May with more than 400 windows smashed -- including an incident Monday.
The latest vandalism involved a 7 train at the 34th Street - Hudson Yards station.
The MTA says the vandal or vandals have caused more than $300,000 in damage and numerous delays -- all at a time when the MTA doesn't have a dime to spare.
There have been 53 incidents in Manhattan, 14 in Queens, 2 in Brooklyn and 1 in the Bronx.
The $10,000 reward will be added to the NYPD Crime Stoppers' $2,500 reward for a total of $12,500.
MTA chief safety officer Pat Warren said one or more people are using weapons to smash out the windows on subway cars -- from inside the trains.
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"This takes considerable force," Warren said. "This has to be done with a blunt instrument of some kind. A hammer, a pipe, a baseball bat. Something significant."
So many windows have been broken that the MTA is running out of replacements. That will soon result in more time between trains - translating to longer waits on subway platforms and more crowded subway trains, two things MTA is actively trying to avoid during the pandemic.
"These vandals don't have the respect for our riders and those essential workers that depend on this service to get them back and forth to work," Warren said.
There are photos of the person police believe is responsible, but the attacks usually happen on empty cars, so there have not been any eyewitnesses. Police say if anyone recognizes the suspect, please give the cops a call because this crime is costly.
MTA says they do not know why there has suddenly been "a considerable" uptick in vandalism.
They say the windows are specially designed and different windows fit different model train cars, and that there simply aren't enough subway train windows in the supply line to repair them at the rate they are currently being broken.
Most of the vandalism seems to happen when passengers are not on the trains, resulting in a frustrating lack of eyewitness accounts. They are still trying to nail down exactly when and where the vandalism is occurring.
"We plead to everybody put on your little detective shields if you see something, say something, certainly make us aware of it and we have the greatest detectives in the world that'll ultimately bring it all together," said Inspector Jason Savino with the NYPD Central Robbery Division.
Anyone with information in regard to this incident is asked to call the NYPD's Crime Stoppers Hotline at 1-800-577-TIPS (8477) or for Spanish, 1-888-57-PISTA (74782).
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