Ten people were taken to hospitals when a taxi jumped a curb and plowed into a group of cab drivers near the city's airport Monday.
There is no information to suggest the crash was intentional, police said. The driver, who has been cooperative from the outset, was released after being interviewed by state troopers. His cab was seized for further investigation.
Police said it appears the driver mistakenly pressed the gas pedal instead of the brake and it's believed to be a case of "operator error.''
The driver was a 56-year-old Cambridge man who worked for Metro Cab. "He is known to be a very nice gentleman to his peers," State Police Major Frank McGinn said at a news conference. He has "no history of violations or anything."
The crash briefly raised fears of terrorism akin to attacks in Britain, Stockholm and Nice, France, where vehicles crashed into groups of people, killing dozens.