The driver of the doomed Chinatown casino bus is a convicted killer who had two licenses — including one he got using an alias.

Ex-con Ophadell Williams is set to be grilled today by probers, who already doubt his tale that he was clipped by a tractor trailer, officials said.

News of the expected showdown among Williams, the National Transportation Safety Board and State Police came as the crash claimed its 15th victim: a 70-year-old man who died from injuries suffered in the horrific smash-up on I-95 in The Bronx.

Gov. Cuomo yesterday ordered the state inspector general to investigate how Williams — who has convictions for manslaughter and grand larceny in addition to a slew of traffic violations — wound up getting a valid commercial-driving license.

In 1995, he was busted once for speeding and twice for driving without a license — all within eight days, sources said. He gave the cops an alias, Erik Williams, at the time.

His license was then suspended because he failed to respond to the charges.

In addition, Williams was busted in 2003 — again for driving without a license.

Nine men and six women were killed early Saturday when the World Wide Tours bus that Williams was driving toppled on the highway and slid into a steel sign stanchion, nearly shearing the vehicle in half. He was ferrying gamblers back to Chinatown from the Mohegan Sun in Connecticut at the time.

Investigators are scrutinizing surveillance video from the casino to see how Williams, 40, spent several hours before departing with his 32 passengers early Saturday morning.

There was a surveillance camera aboard the bus, but it wasn’t turned on, source said.

“We want to know what he ate, what he drank, how much he slept, everything we can find out,” said NTSB Vice Chairman Christopher Hart.

Witnesses and passengers had reported that Williams — who later passed a Breathalyzer test — swerved onto the highway’s shoulder several times, possibly after nodding off. He claims he was clipped by a truck before the crash occurred.

But “there does not seem to be any evidence of a truck hitting the bus,” Mayor Bloomberg said yesterday.

Investigators also are looking into why Williams apparently hadn’t updated his log book, in which he’s required to record all of his trips, for several days before the crash.

Meanwhile, details of Williams’s sordid criminal past came to light.

In 1990, he knifed a man to death during an argument and served two years behind bars.

Four years later, he was busted for cashing a purloined check from the Police Athletic League worth $83,905 and served six more years in prison.

His most recent driving bust — for not having his license — occurred June 4, 2003, while he was still on parole for the PAL scam.

Williams was released from St. Barnabas Hospital in The Bronx on Sunday evening after being treated for a neck injury.

World Wide Tours did not return a call for comment.

A family friend of Williams, Derrick Brown, 29, said yesterday that the driver “is feeling very depressed . . . I saw the tears in his eyes.

(Source: NY Post)