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SAN DIEGO (CBS 8) - Former Chargers star Junior Seau died of a self-inflicted gunshot wound to the chest, the San Diego County Medical Examiner's Office said Thursday.
Seau's family has been asked to donate his brain for research into the effects of repetitive injury. It was unknown if the family has made a decision.
The medical examiner's full report could take up to 90 days to complete.
THIS IS A STORY UPDATE. For an earlier version, read below.
OCEANSIDE (CBS 8) - The San Diego County Medical Examiner's office is expected to complete an autopsy on Junior Seau's remains Thursday, as Oceanside police continue to investigate the apparent suicide by the former Chargers linebacker.
The Oceanside Police Department received a call at 9:35 a.m. Wednesday, May 2 from a young woman claiming to be the girlfriend of Junior Seau. She said that she had returned to the house and found Seau unconscious with a gunshot wound to the chest, according to Oceanside Police Chief Frank McCoy.
Police and fire crews responded to the residence in the 600 block of The Strand South in Oceanside and found Seau's body in one of the bedrooms. Life saving efforts were performed, however, the efforts were not successful. It was at that time that a handgun was found near the body.
"This case at this point is being investigated as a suicide," McCoy said, adding that the investigation is ongoing at this time.
The NFL great's mother, Luisa Seau, tearfully implored the crowd gathered in front of his seaside house to "show your love to my son."
"I prayed to God, 'Take me, leave my son,' but it's too late, too late," she said in a grief-choked voice.
The former footballer's sister, Annette, praised her late sibling and asked for privacy for her family during its time of mourning.
"My brother was a loving brother, a caring citizen," she said.
San Diego Mayor Jerry Sanders hailed Seau as "one of the most electrifying athletes in San Diego sports history."
"He was a passionate figure who gave the game of football -- and Chargers fans everywhere -- everything he had," Sanders said. "His passion for the San Diego region was also felt through his charitable work, which did so much good in so many ways."
First reports of Seau's death came from TMZ and were followed by calls to the News 8 newsroom from neighbors of Seau reporting that he had committed suicide.
After hearing the news, many have posted messages on their social media accounts in honor of Junior Seau. Here are a few of those messages:
San Diego Chargers via Facebook:
"Everyone at the San Diego Chargers is in complete shock and disbelief right now. We ask everyone to stop what they're doing and send their prayers to Junior and his family."
Chargers owner Dean Spanos:
"I can't put into words how I'm feeling right now. I'm shocked and devastated. Junior was my friend. We all lost a friend today. Junior was an icon in our community. He transcended the game. He wasn't just a football player, he was so much more. He was loved by everyone in our family, our organization and throughout the NFL. This is just such a tragic loss, one of the worst things I could ever imagine. My prayers go out to Junior's family. It's heartbreaking."
Chargers Head Coach Norv Turner:
"I have no words to describe the passing of Junior Seau. This is a sad, sad day, not only for me, but for the whole sports community. I worked with Junior here and later in Miami. I can tell you no one had more character and true leadership ability than Junior. He brought passion to the game of football that was unmatched. His commitment to charitable causes in the community was inspiring. It was an honor to know him. My thoughts and prayers are with his family.
NFL Commissioner Roger Goodell via Twitter:
"All of us are deeply saddened about Junior Seau, a great player loved by teammates who also worked hard to serve his community."
Terrell Owens via Twitter:
"God Bless Junior Seau & his family! My heart & condolences go out 2 his family. May u RIP!"
Deion Sanders via Twitter:
"Junior Seau will certainly be missed. A great football player but a better man. He was classy,caring & courageous.God bless the Seau family"
Chad Ochocinco via Twitter:
"My prayers and condolences to the family of one of the NFL's greatest linebackers to ever play the game.. Junior Seau.. R.I.P"
Reggie Bush via Twitter:
"Damn this one hurts San Diego! One of the greatest to to come from the city."
Mark Ingram via Twitter:
"#RIP Junior Seau Such a great player I watched growing up!! My prayers and condolences go out to his family!! Sad to hear.."
Jacob Hester via Twitter:
"Really sad news about Junior Seau. Very few players can be the soul of a city like he was in San Diego. One of the All time greats."
Tony Hawk via Twitter:
"Goodbye Junior Seau, you were an inspiration for turning success into greater good. Thank you for making San Diego a better place for youth."
County Supervisor Ron Roberts via Twitter:
"Junior Seau's untimely passing strikes a deep chord in all of us.We were lifted by his enthusiasm for life, on the field and everyday."
Seau led the Chargers to the Super Bowl, following the 1994 season. He stayed with the Bolts until 2003 and then played with the Miami Dolphins and New England Patriots. He retired after the 2009 season.
On Oct. 18, 2010, Seau was arrested after his 25-year-old live-in girlfriend reported that he had assaulted her during an argument. Later that morning, five hours after bailing out of jail, he drove his 2004 Cadillac Escalade over a rocky 30-foot coastal cliff and onto Carlsbad State Beach, suffering minor injuries.
Seau told police he had fallen asleep at the wheel.
Prior to his professional career, Seau was a standout linebacker with the University of Southern California.
USC head football coach Lane Kiffin said Seau recently attended the Trojans' spring game at Los Angeles Memorial Coliseum.
"This is a very sad day," Kiffin said. "The USC football program and the entire Trojan Family extends our condolences to Junior's family. He was one of the greatest Trojans of all time."
USC athletic director Pat Haden added, "Junior Seau was one of the greatest legends in USC football history. He will always be remembered by USC as the original No. 55."
In 1992, Seau created the Junior Seau Foundation, an organization formed "to educate and empower young people through the support of child-abuse prevention, drug and alcohol awareness, recreational opportunities, anti-juvenile delinquency efforts and complimentary educational programs."
Junior Seau was 43 years old. He is survived by a daughter and two sons.