But Assistant District Attorney Brendan O'Malley said that the three men "ambushed" Kless, that the attack was "unprovoked" and that it is "certainly a murder case."
Philadelphia Common Pleas Judge Patrick F. Dugan continued the preliminary hearing until May 14 after defense attorneys requested a continuance to prepare written motions. The judge will then determine the charges for trial.
Defense attorneys say they have evidence - which was not disclosed at Wednesday's hearing - that words were exchanged between Kless, 23, and the defendants before the attack.
They said Kless had a blood-alcohol level of .262, more than three times the legal limit for driving in Pennsylvania. (Kless was not driving when he was attacked.)
Kless' girlfriend, Kerri Holland, calmly testified that she and Kless were walking arm-in-arm on Chestnut Street near 4th about 2:30 a.m. Jan. 14 when two men approached them from behind.
"The next thing I know, Kevin is ripped from my right arm," Holland said.
Holland testified that both Carillo and Santiago then began striking Kless on the sides of his head with "closed fists" as he attempted to fend off the blows.
She said a third man she couldn't identify then delivered a single punch, and Kless fell to the pavement with his face up.
O'Malley said that the third man is Ferguson and that he delivered the fatal blow. "Mr. Kless was dead before he hit the ground," the prosecutor said.
An assistant medical examiner testified that the blow snapped Kless' head around, ripping an artery.
Homicide detective John McNamee testified that Ferguson waived his Miranda rights and gave cops a 10-page statement Jan. 20.
McNamee said Ferguson told cops he hit Kless twice. "I guess he lost consciousness and fell, and I guess he hit his head," Ferguson said, according to his statement read by McNamee. "Then we left because it looked serious. I didn't expect the guy to die."
Contact Michael Hinkelman at 215-854-2656 or firstname.lastname@example.org, or follow on Twitter @MHinkelman.