A Roslindale man was ­acquitted on Friday of stabbing two people, one of whom was killed, on an MBTA bus in ­November 2010, officials said.

A Suffolk Superior Court jury acquitted Kim Gross Jr., 20, in the slaying of Richard Allen, 21, of Roxbury, and stabbing another 18-year-old man whose identity was never released, according to a statement from Suffolk District Attorney Daniel F. Conley’s office on Friday. The stabbing ­occurred aboard the Route 44 bus traveling toward Ruggles station on the morning of Nov. 2, the statement said.

Jurors made their decision after six days of testimony from more than two dozen witnesses, the statement said. They deliberated for about two hours.

According to authorities, the trial included eyewitness statements, cellphone and tower records, surveillance ­imagery, and CharlieCard ­account information that linked Gross to the stabbings.

“We gave the jury everything it needed to convict,” Jake Wark, spokesman for the Suffolk district attorney, said in an e-mail. “It’s hard to see how the jury could weigh that evidence in just two hours of deliberations.”

The attack took place outside the William Monroe ­Trotter Elementary School in Roxbury, and a school nurse rushed outside to try to help the victims. Authorities believe the stabbings were gang-­related, Wark said.

Family members previously told the Globe that Allen was to become a father a few months after the stabbing ­occurred.

Gross was held on $20,000 cash bail after a March indictment on unrelated gun and drug charges, the statement said. He is expected to return to court June 18.

Gross’s lawyer did not ­immediately return calls for comment. His family also could not be reached.