The March 18 suicide of Muslim-American recruit Raheel Siddiqui days after he began boot camp at Marine Corps Recruit Depot Parris Island, South Carolina, highlighted allegations of hazing and resulted in the firings of several senior officers and leaders at the depot.

But abuse and maltreatment of recruits did not begin or end with Siddiqui, Military.com has learned.

In all, three different investigations into training inside one Parris Island battalion reveal a culture of hazing and violence that did not end until one recruit's family sent an anonymous letter to President Barack Obama in April.

The investigations also reveal that drill instructors within 3rd Recruit Training Battalion had a history of singling out recruits based on their ethnicity and religion, and that another Muslim recruit had been subjected to severe hazing in 2015 when a drill instructor repeatedly shoved him into a clothes dryer and turned it on, and forced him to shout "Allah Akbar" loud enough to wake other recruits.

That same drill instructor would become a supervisory drill instructor in Siddiqui's unit, the investigation found, and his treatment of the recruit, including forcing him to complete "incentive training" and physically assaulting and slapping him immediately prior to his death, provided impetus for the suicide, investigators found.

Punitive Action

In all, 20 drill instructors and senior leaders from Parris Island's Recruit Training Regiment face punitive action or separation from the Marine Corps for participating in or enabling mistreatment of recruits. Several drill instructors at the heart of the abuse allegations are likely to face court-martial for their actions.

The contents of the three investigations have not been released publicly as the findings have yet to be endorsed by Lt. Gen. Robert Walsh, commanding general of Marine Corps Combat Development Command. But Marine officials discussed the contents of the investigations and the recommendations of the investigating officers in response to a public records request.

Marine officials said Thursday that the incidents of hazing and abuse were confined to 3rd Recruit Training Battalion and not indicative of the culture within the Corps' boot camps at Parris Island and San Diego.

"When America's men and women commit to becoming Marines, we make a promise to them. We pledge to train them with firmness, fairness, dignity and compassion," Marine Corps Commandant Gen. Robert Neller said in a statement. "Simply stated, the manner in which we make Marines is as important as the finished product. Recruit training is, and will remain, physically and mentally challenging so that we can produce disciplined, ethical, basically trained Marines."

A lengthy investigation into the death of 20-year-old Siddiqui found the recruit had died by suicide, jumping from the third floor of the Company K recruit training barracks, slamming his chest against a railing at the bottom of the stairs.

Siddiqui had threatened to kill himself five days before, prior to the first full day of recruit training. He described a plan to jump out a squad bay window, investigators found, but later recanted and was allowed to remain in training.

Singled Out

In the short time Siddiqui was at the unit, investigators found he was repeatedly referred to as a "terrorist," presumably in reference to his Muslim background. One drill instructor also asked the recruit if he needed his turban, officials said.

Findings show recruits were routinely singled out on account of their backgrounds and ethnicity. Drill instructors referred to one recruit born in Russia as "the Russian" and "cosmonaut" and asked him if he was a communist spy, investigators found.

In Siddiqui's unit, recruits were subjected to unauthorized incentive training, in which they would lift footlockers, day packs and other heavy items and clean the squad bay in uncomfortable positions using small scrub brushes for hours. Drill instructors would also push and shove recruits and use Marine Corps Martial Arts Program training as an opportunity to pit recruits against each other, sometimes in physically unfair matchups.

Drill instructors told investigators that a more experienced drill instructor taught subordinates they needed to "hate" recruits to be successful at training them.

On March 13, Siddiqui, who previously had received a clean mental health evaluation, expressed a desire to kill himself. He was interviewed at the scene and turned over the the depot's mental health unit, where he recanted and expressed a wish to return to training.

He was given a clean bill of health, described as "highly motivated to continue training," and returned to his unit with no follow-up requested, investigators found.

Drill instructors would tell investigators that recruits frequently express suicidal ideations as an excuse to get out of training, and thus no serious incident report was made about Siddiqui's threat. While drill instructors were told to ease Siddiqui back into training, they were not made aware of his suicidal ideations.

The morning of Siddiqui's death, the recruit presented drill instructors with a note asking to go to medical with a severely swollen throat. He claimed he had lost his voice and coughed up blood overnight and was in significant pain. In response, he was told to do "get-backs" -- to sprint back-and-forth the nearly 150 feet between the entrance to the bathroom, the back of the squad bay and the front of the squad bay.

"I don't care what's wrong with you; you're going to say something back to me," a drill instructor yelled as Siddiqui began to cry.

Shortly after, the recruit dropped to the floor clutching his throat, though it's not clear if he became unconscious or was feigning to deflect the drill instructor's abuse.

In an effort to wake him, the drill instructor slapped Siddiqui on the face hard enough to echo through the squad bay. The recruit became alert, ran out of the squad bay, and vaulted over the stairwell railing, sustaining severe injuries in the fall.

Drill instructors called 911. Siddiqui would be taken to Beaufort Memorial Hospital, then airlifted to Charleston, where he would receive blood transfusions and emergency surgery in an unsuccessful effort to save his life. He died just after 10 a.m.

The lawyer for the Siddiqui family, Nabih Ayad, did not immediately respond to requests for comment regarding the investigations' findings.

Leaders Relieved

In the wake of Siddiqui's death, multiple leaders have been relieved for failing to prevent the culture of recruit abuse. On March 31, 3rd Recruit Training Battalion Commander Lt. Col. Joshua Kissoon was fired in connection with the investigation of prior allegations of recruit mistreatment, including the hazing and assault of another, unnamed, Muslim recruit.

Notably, the Marine Corps' investigations stopped short of finding that drill instructors' hazing of Siddiqui and other recruits was motivated by racial bias. They did find evidence that some drill instructors made a practice of exploiting recruits' ethnicities as a way to harass them.

On June 6, Parris Island officials announced that Recruit Training Regiment's commander, Col. Paul Cucinotta, and its senior enlisted leader, Sgt. Maj. Nicholas Dabreau, had been relieved in connection with the Siddiqui investigation.

Fifteen drill instructors have been sidelined since April amid allegations of recruit hazing and maltreatment, and two captains may also face punishment for failing to properly supervise drill instructors.

Marine officials said it may be one to three months before disciplinary decisions are made, including possible charges filed, regarding these 20 Marines.

Officials with Marine Corps Training and Education Command have also set in motion a host of new policies designed to prevent future mistreatment of recruits, said Maj. Christian Devine, a Marine Corps spokesman.

These include increased officer presence and supervision of recruit training; mandatory suspension of personnel being investigated for recruit hazing or mistreatment; better visibility of investigations above the regiment level, changes to the drill instructor assignment process to prevent chain-of-command loyalty from affecting leadership; creation of a zero-tolerance policy for hazing among drill instructors; and a review of mental health processes and procedures for suicide prevention.

"We mourn the loss of Recruit Siddiqui," Neller said. "And we will take every step necessary to prevent tragic events like this from happening again."

-- Hope Hodge Seck can be reached at hope.seck@military.com. Follow her on Twitter at@HopeSeck.