The baby weighed only about 4 pounds when he was delivered, neighbors and friends said. He died of extreme prematurity, the city medical examiner's office said.
The driver of the livery cab, Pedro Nunez Delacruz, was knocked unconscious but was not seriously hurt. His vehicle should not have been sent to pick up the passengers because an application to use the Toyota as a livery cab had not yet been approved, the city Taxi and Limousine Commission said.
Acevedo, 44, was arrested last month on a charge of driving while under the influence, and the case is pending. He served about a decade in prison in the 1990s for manslaughter. No one answered the door at Acevedo's last known address, in a public housing complex in Brooklyn. Neighbors said his mother lived in the same building, but she did not answer her door.
"We in the community are demanding that the prosecutor charge the driver of BMW that caused the death of this couple and infant ... with triple homicide," Abraham said in a statement. "This coward left the scene of the accident not even bothering to check on the people of the other car."
How Acevedo came to possess the BMW is also under investigation. The registered owner, Takia Walker, was arrested on insurance fraud charges Sunday in a scam involving the car, police said. She was not involved in the crash. A telephone number registered to Walker rang unanswered.
A person familiar with the investigation said Walker bought the car legally, or allowed her identification to be used in the purchase, then gave the vehicle to a middleman who either lent or rented it out to the driver. The person was not authorized to speak publicly and spoke to The Associated Press on condition of anonymity.
Associated Press Writer Jim Fitzgerald in Kiryas Joel, N.Y., contributed to this report.