Surveillance video of the 2006 rampage captured Brian Hooks, 21, and Thomas Daugherty, 19, repeatedly hitting one of the victims, causing national outrage among the homeless community.
Hooks and Daugherty were found guilty of second-degree murder as well as two counts each of attempted second-degree murder with a weapon for beating two other homeless men.
Prosecutors said Norris Gaynor, 45, was sleeping on a park bench when the men, who were then teens, beat him to death. Prosecutors said Hooks and Daugherty were drunk that night, concealed the bats in their pants and then hide before sneaking up on their victims.
The surveillance footage shows a surviving victim desperately trying to cover his body from numerous blows.
Defense attorneys had argued the teens never intended to kill Gaynor and urged the jury to consider a lesser charge of third-degree felony murder.
They also tried to cast doubt on earlier testimony from William Ammons, 21, who pleaded guilty in May to felony murder and aggravated assault in the beatings. They said Ammons had a "biased interest to fabricate facts in the case to save" himself and has admitted lying to police 80 times.
Ammons will face between 10 and 20 years in prison. He is awaiting sentencing.
Jacques Pierre, 61, was assaulted first in the attack captured on video.
Ammons confessed to hitting a third man, 51-year-old Raymond Perez, with a plastic sword and admitted that he fired shots from a paintball gun at Gaynor. A prosecutor said Ammons did not hit anyone with a baseball bat or other deadly weapon, a key factor in his plea to lesser charges.