Now, he's voicing his support a second time, telling the San Francisco Chronicle on Monday that he does not believe the NFL should suspend McClain based on the information he has on McClain's case.
"I'm taking a stand behind my player," Jackson said.
McClain was arrested in Alabama last Thursday on misdemeanor assault, firearms and other charges. The linebacker allegedly put a gun to his ex-high school basketball teammate's head and fired a shot past his ear. McClain declined to comment on Monday, the Chronicle reported.
Jackson told reporters, however, that after conducting some "fact-finding" he believes McClain simply was in the wrong place "at the wrong time."
When all the details of the case are known, Jackson said, "I think maybe ... we'll all feel different about it."
The Chronicle reported the NFL is conducting its own investigation into the incident. If the league decides the suspension is warranted, Jackson said his views on McClain will change dramatically.
"(I will) come down hard (on him)," Jackson said. "That would mean that someone's not being truthful."
In other Raiders news, Jackson also told reporters that he did not feel an ejection was justified for defensive end Richard Seymour. Seymour was tossed from Sunday's loss after throwing a punch at Dolphins lineman Richie Incognito. Jackson said he believed it was merely a "glancing blow" and was unintentional.