New details on the mass robbery of passengers on a nighttime BART train at Oakland’s Coliseum Station are emerging — including revelations that:

•The operator of the Dublin-bound train allowed the automatic doors to open, letting a mob of as many as 60 youths storm aboard, even though they were beating on the doors and windows.

•The same crowd of youths had swarmed a San Francisco-bound train at the same station just minutes before, fleeing only when they found no one to rob.

•Four of the nine cars on the Dublin train didn’t have working surveillance cameras, including the car where at least some of the victims were robbed and beaten.

According to passenger Rusty Stapp of Dublin, who just filed a $3 million claim with BART stemming from the April 22 episode, it was clear as the train rolled up to the Coliseum Station platform that things were going to turn out badly.

“They were banging on the windows even before the train stopped,” Stapp said.

“We could hear the conductor over the intercom telling the crowd to stand back or the doors would not open,” Stapp said. “Then two seconds later, the doors opened.”

The teens rushed in, pummeled Stapp and stole his wife’s purse, robbed other passengers and ran from the train, Stapp said.

BART spokeswoman Alicia Trost conceded that the teens were waiting for the train when it pulled in and that they had jumped the fare gates to get there.

“But this train operator hadn’t been advised of the fare evasion, since it had just occurred moments before,” she said.

Trost said train operators can override the automatic controls and keep doors from opening. But an operator gets only a brief look at a platform as the train speeds into a station, and he or she is often looking at the tracks to make sure they are clear, Trost said.

She added that this operator might not have known that the mob of youths was pounding on the train before the doors opened.

“The operator hadn’t received word not to allow this to happen, since the police had just been called moments before,” Trost said.

She said the entire incident, from the moment the youths entered the station to the time they ran off, took four minutes. “It all occurred very fast,” she said.

When Stapp was interviewed by BART police, he was shown video of the same teens swarming a San Francisco-bound train minutes before, then coming back onto the platform to wait for the Dublin train.

Trost confirmed the earlier incident, but said “no crimes were committed.”

As for surveillance cameras, Stapp said police told him they had no video from the car he was in — nor any from the two adjacent cars or the lead car, where the operator sits.

BART has said it has surveillance video from some of the cars and station. But it has declined to release it, saying the footage appears to show juveniles whose identities would be withheld if they were arrested.

BART has since announced the arrest of two juveniles suspected of being part of the robbery mob.

Political poker: Lt. Gov. Gavin Newsom would like us to think that his release of six years of personal tax returns was in response to President Trump’s refusal to release his taxes — a first for a president in 40 years.

“There has been a lot of noise about what Trump may be hiding, and Gavin feels the public has a right to know how its elected officials have made their money,” said Newsom spokesman Dan Newman.

Newsom’s decision to lead by example, however, is also aimed a little closer to home — the targets being two possible Democratic opponents in his 2018 race for governor, former Los Angeles Mayor Antonio Villaraigosa and billionaire hedge fund operator Tom Steyer.

Newsom is looking to put pressure on Villaraigosa to disclose which businesses, unions or other interest groups he’s worked for since he left L.A. City Hall in 2013. One of those was Herbalife, the nutritional supplement company that agreed last year to pay a $200 million federal fine over questions about its marketing practices.

As for Steyer, Newsom wants the public to see the extent of the hedge fund operator’s investments.

Such financial disclosures are little trouble for either Newsom or his other major rival in the governor’s race, state Treasurer John Chiang. Both have years of public office under their belts that call for yearly financial disclosure statements.

Plus, it’s common knowledge that Newsom and his actress/filmmaker wife, Jennifer Siebel Newsom, are loaded.

The couple’s returns show the Newsoms paid about $500,000 a year in taxes at a rate of 36 percent, and gave about $100,000 a year to charities.

Gavin Newsom’s income comes from a number of sources, including restaurant, resort and wine investments he made with the Getty family.

Siebel Newsom’s income comes, in part, from a blind family trust.

Villaraigosa campaign strategist Eric Jaye said his candidate will match Newsom in releasing six years of income taxes in a matter of “months, but not days or weeks.”

“Gavin has been running for nine years, and Antonio for five months,” Jaye said. “If you asked for income taxes for six years on 24-hour notice, you couldn’t do it.”

As for Steyer, a spokesman said someone would get back to us. We’re still waiting.

San Francisco Chronicle columnists Phillip Matier and Andrew Ross appear Sundays, Mondays and Wednesdays. Matier can be seen on the KPIX TV morning and evening news. He can also be heard on KCBS radio Monday through Friday at 7:50 a.m. and 5:50 p.m. Got a tip? Call (415) 777-8815, or email matierandross@sfchronicle.com. Twitter: @matierandross