Sergio Brown, Myrtle Brown.Photo:Dan Mullan/Getty Images; Family Handout

Sergio Brown of the Jacksonville Jaguars helps to coach a team of local school children during the NFL Launch of the Play 60 scheme; Myrtle Brown - Mother of missing ex-NFL player Sergio Brown was fatally assaulted

Dan Mullan/Getty Images; Family Handout

The Cook County Medical Examiner’s Office previously told PEOPLE that Myrtle’s death is being investigated as a homicide, and that she died as a result of “multiple injuries due to assault.”

According to Wednesday’s press release, Sergio was taken into custody in San Diego while “re-entering” the United States after being in Mexico and “is awaiting extradition to Maywood, IL, to face charges of First-Degree Murder.”

Sergio played in the NFL for six seasons, signing with the New England Patriots in 2010 and retiring following the 2016 season, during which he played for the Bills.

Days after his mother’s death, disturbing social media videos from Sergio began to surface. Avideoappearing to be Sergio was posted on an Instagram account with the username “intplayerwithapassport." (As of Wednesday, the Instagram account is no longer active.)

Myrtle Brown.

Myrtle Brown - Mother of missing ex-NFL player Sergio Brown was fatally assaulted

While Sergio didn’t explicitly refer to his mother’s death in the video, he said “it has to be the FBI,”PEOPLEreported previously. He then claimed that the bureau paid him an “unwarranted” visit on “Bob Marley’s death day." He also claimed the Maywood Police Department “kidnapped” him on two occasions.

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In the since-deleted video, he also said he thought Myrtle was “on vacation,” and that “it had to be the FBI or Maywood PD,” without explicitly stating what “it” referred to.

Sergio Brown.Dan Mullan/Getty Images

Sergio Brown of the Jacksonville Jaguars helps to coach a team of local school children during the NFL Launch

Dan Mullan/Getty Images

Two days later, he appeared in another video on the same Instagram account, singing a Drake song and making references to dying.

It is unclear if Sergio has retained an attorney to speak on his behalf.

Before Sergio’s arrest, his brother, Nick Brown, spoke out in a post onFacebookabout his mother’s death and Sergio’s disappearance.

“Mom, thank you for being strong, caring, diligent, fancy, funny, and for saving my art,” he wrote in part. “I won’t let you down. My brother Sergio is still missing. If anyone knows where he is I want him to know that I love you and please come home.”

After news of the arrest, Myrtle’s sister Sheila Simmons shared a statement from a representative for the family on herFacebook.

source: people.com