BUFFALO, N.Y. -- Jeffrey Basil has pleaded guilty to first-degree manslaughter in the death of Air National Guardsman William Sager Jr.

In accepting the plea bargain, Basil admitted to pushing Sager down the stairs at Molly's Pub in May 2014, intending to cause him serious physical injury. 

Basil was convicted by a jury in January 2015 of murdering Sager, meaning he intended to cause his death. But the verdict was set aside last month after Basil's defense attorneys learned one of the jurors failed to disclose information about her background during jury selection. 

The judge determined that Basil did not have a fair and unbiased jury. Following the judge's decision, both sides came to an agreement that this was the best way to move forward, as there would be no guarantees if the case went to trial for a second time. 

"We would have run the risk of possibility of being convicted of murder. And if that happened, at sentencing Jeff Basil would be looking at a possible life sentence. So we felt that this was our best option. And it was clearly in his best interests," defense attorney Joel Daniels said.

"The Sager family was consulted and agreed with this disposition because this gives closure to them and a guaranteed sentence, which is appropriate for this crime," said Michael Flaherty, first assistant Erie County district attorney.

As part of the deal, Basil's sentence will be between 15 and 21 years in state prison. If he had been convicted of first-degree manslaughter by a jury, the minimum sentence would have been eight years. Basil also had to waive his right to an appeal. 

Sentencing is scheduled for July 22.