After about a day of deliberations, a jury Thursday found Justin P. Gonzalez guilty of involuntary manslaughter in the 2012 death of Nicholas Sardina at a house party in Lawrence.

The defense plans to appeal.

Members of Gonzalez’s family cried, some uncontrollably, as the verdict was read.

Gonzalez, 23, of Mission, hit Sardina, 27, of Lawrence, over the head with a beer bottle during a brawl at a party in the 300 block of West 14th Street in the early morning hours of Feb. 25, 2012. Gonzalez had argued that he was trying to protect a friend under attack by Sardina. Prosecutors said Gonzalez used excessive force in striking Sardina, who later died from his injuries.

The first trial in December ended in a hung jury. The retrial began last Wednesday.

“This was a difficult and tragic case. One family has to deal with the loss of a loved one and Mr. Gonzalez will have to live with the fact he took a life,” District Attorney Charles Branson said in a statement Thursday. “No matter the outcome of the second trial, we felt the community should decide this case.”

Gonzalez, who remains free on bond, faces probation to 34 months in prison because of his lack of criminal history, according to his lawyer. A sentencing scheduling hearing has been set for June 17.

Defense attorney Sarah Swain said she would be appealing the verdict on the grounds that the court gave the jury improper instructions on how to convict and should have allowed the jury to hear about Sardina’s history of violence. She said she will also push the judge to sentence her client to probation.

“Justin Gonzalez is a very nice, responsible young man. He has a very bright future,” Swain said. “His father passed away unexpectedly during the course of this case, so he has taken on the responsibility of being the man in the family.”

Gonzalez’s aunt, Nancy Bennett, said the state relied on a “bunch of drunks” to prove its case rather than people who were sober at the party that night and could have testified that her nephew was only trying to protect his friends.

“But that’s our court system these days,” added Gonzalez’s uncle, Anthony Gonzalez. “It’s all about winning the case and not so much allowing justice to take place.”

The jury interrupted its deliberations Thursday morning to rehear testimony from Jake Anderson, the friend of Gonzalez’s who got into the initial altercation with Sardina. Anderson had testified during trial that he didn’t feel like he needed help during the fight, and that Gonzalez told him he picked up a beer bottle and struck Sardina with it after he saw him punch Anderson. Gonzalez, however, testified that he struck Sardina with a Dos Equis bottle he was drinking from because he feared for Anderson’s life.