Wells says his inquiry found Martin was taunted and ridiculed almost daily. After Martin left the team in October, Incognito boasted about "breaking Jmart" in a notebook the linemen used to tally fines and bonuses among themselves. When the investigation began, Incognito asked another player to destroy the book, but investigators obtained it.
The other harassed player was "subjected to homophobic name-calling and improper physical touching," while the assistant trainer, who was born in Japan, was subjected to racial slurs.
"It was not difficult to conclude that the Assistant Trainer and Player A were harassed, but the questions raised in Martin's case were more complex, nuanced and difficult," the report says.
Although Wells concluded that Martin was abused by three teammates, he qualified some of the assertions in Martin's account.
Evaluating Martin's claims was difficult, "given his mental health issues, his possible heightened sensitivity to insults and his unusual, 'bipolar' friendship with Incognito," the report said.
"Nonetheless, we ultimately concluded that Martin was indeed harassed by Incognito, who can fairly be described as the main instigator."
In a statement emailed by a league spokesman, the NFL did not make any mention of possible punishment stemming from the case. Instead, the league confirmed that it had received Wells' report, and said it appreciated the Dolphins' cooperation with the investigation.
Wells said he does not intend to comment further.
The report comes about three months after Wells was retained by the league to investigate the case, which prompted a national debate about hazing and workplace bullying.
Martin told investigators Incognito joked that he and other teammates would rape Martin's sister, a medical student none of them had ever met. Incognito also called Martin various racial slurs, made jokes about slavery and routinely demeaned Martin for not being "black enough."
The report said Pouncey and Jerry followed Incognito's lead.
"To a great extent, Incognito dictated the culture," the report said. "We doubt that matters would have gotten so out of hand had Incognito not set a tone on the offensive line that made extremely vulgar taunting a typical form of communication."
The 6-foot-5, 312-pound Martin abruptly left the team Oct. 28. He was briefly hospitalized and then joined his family in California and underwent counseling for emotional issues. Incognito was barred from the season's last eight games.
Incognito expressed regrets about the racist and profane language he used with Martin, but said it stemmed from a culture of locker-room "brotherhood," not bullying.
Martin has said he tried to be friends with Incognito. The two players traded more than a thousand text messages in a year's span, and the teasing and vulgar banter went both ways, with references to sex, drugs, violence and bawdy behavior, often in a jocular tone.
According to the report, Martin was particularly offended over the three men talking openly in front of teammates about wanting to have sex with his sister.
The report said Incognito, Jerry and Pouncey repeatedly and persistently made graphic, sexually explicit comments about Martin's sister.
Martin repeatedly blamed himself in text messages to his parents for not standing up to his teammates, saying he went out of his way to avoid confrontation. The report said Martin at one point he went into the bathroom of a yacht and cried after repeated racial slurs.
The report also found that Incognito, Jerry and Pouncey donned traditional Japanese headbands that featured a rising sun emblem on the anniversary of the 1941 attack that brought the U.S. into World War Two and jokingly threatened to harm the assistant trainer as retaliation for the attack on Pearl Harbor.
According to Martin, the assistant trainer confided in him that he was upset about the Pearl Harbor comments, finding them derogatory toward his heritage.