The jury began deliberating Wednesday in the retrial of Justin P. Gonzalez, who is charged with involuntary manslaughter in the 2012 death of Nicholas Sardina, 27, of Lawrence.

Gonzalez, 23, of Mission, hit Sardina in the head with a beer bottle during a fight at a party in Lawrence on Feb. 25, 2012. Sardina died hours later, the result, prosecutors say, of a blood clot in the brain caused by blunt force trauma.

At issue is whether Gonzalez acted recklessly or with reasonable force in an effort to rescue a friend. The first trial last December ended in a hung jury.

Gonzalez, the defense’s only witness, finished testifying in own defense Wednesday morning before the state and defense offered their closing arguments. Gonzalez, who had to compose himself before he could get started, demonstrated how he held the beer bottle before striking Sardina with it: around the label. The prosecution, however, said DNA on the lip of the Dos Equis bottle did not match that of Gonzalez, meaning he likely wasn’t drinking the beer the entire time, as he has claimed, but picked it up to hit Sardina.

In his closing argument, senior assistant district attorney James McCabria said Sardina was not the “raging, red-faced, angry person” the defense has made him out to be at trial, and that it’s not fair to question his mental acuity just because he served two tours of duty in Iraq. Instead, McCabria said, Sardina was a military veteran and college student who had a nice dinner with a former girlfriend the night of Feb. 24, 2012, before going out with friends. Early the next morning, they ended up at the same house where Gonzalez and his friends were having a going-away party. One of Gonzalez’s friends, Jake Anderson, was severely intoxicated and started egging Sardina on, McCabria said; Sardina stood up, Anderson yelled an obscenity regarding “frat guys,” and Sardina pushed Anderson.

“Is Nick’s reaction so unreasonable?” McCabria asked. Plus, he said, police only saw a small bruise on Anderson’s face — does that square with Gonzalez’s testimony that he thought Sardina was going to kill Anderson? And in a room full of his friends, some of them former high-school football players and future military members, how much danger could Anderson have been in? McCabria said witnesses testified that Sardina was calm and coherent after the fight, not exactly a raging mad man.

Defense attorney Sarah Swain began her closing argument by saying “that the best indicator of future behavior is past behavior,” and that, before the February 2012 fight, Gonzalez was never violent and hadn’t ever been in a physical altercation. Sardina, on the other hand, was a hockey player who worked out regularly; did two tours of duty in Iraq, where he was involved in an IED explosion; and was prescribed the anti-anxiety drug Xanax. On the night in question, Swain added, Sardina had several strong alcoholic beverages and took one Xanax and snorted another in front of his former girlfriend. Swain said Sardina was a “drug-crazed, drunken mind who was ready to explode.”

She also argued that Sardina’s consumption of alcohol, Xanax and cocaine may have contributed to his death. Expert witnesses for the state, however, testified that while a preliminary drug screening of Sardina was positive for cocaine, a subsequent test showed he did not have the drug in his system. Those same witnesses also testified that Sardina likely had a blood-alcohol level of .08 — the legal limit for driving in Kansas — and a “therapeutic” amount of Xanax in his system at the time of his injury.

Swain said her client wasn’t acting recklessly; he wasn’t “running around the room hitting people with beer bottles.” He was defending his friend from a “much larger person,” she said (Sardina was about 2-3 inches taller and 30 pounds heavier than Anderson). “Justin was not looking for a fight that night.”

“On Feb. 25, 2012, in the blink of an eye, Justin Gonzalez had to make a decision … to step in or not,” she said. “Based on everything he saw or heard or felt, he believed — and rightfully so — that Nicholas Sardina was not going to stop until Jason Anderson was seriously hurt or dead.”

McCabria added that while no one intended to take a life that night, if anyone else’s blow had killed someone he would also be held responsible.

“Is this a good situation we’re dealing with?” he said. “Is this is an unfortunate situation? It certainly is that.”

Members of the jury started deliberating at around 1 p.m. Wednesday and will continue Thursday morning. Their decision must be unanimous.