Brown, 35, appeared to be in Mexico when he shared the video in which he claimed he thought his mother, Myrtle Brown, 73, whom he shared a home with, was on vacation at the time of her reported death. The former NFL safety also seemed to accuse local police and the FBI of potentially being responsible for his mother's death.
The Maywood Police Department, which has not labeled Brown a suspect in his mother's death, said it was "aware of the video" and was investigating "its authenticity" in an emailed statement to the Chicago Sun-Times on Tuesday.
“Maywood Police Department detectives are aware of a video that has surfaced on social media in relation to Mr. Sergio Brown, who is still considered a missing person and are also looking its’ authenticity,” a department spokesperson said.
Carlos Cortez, a neighbor who said he last saw Sergio and Myrtle Brown in person on Thursday (September 14), provided police with Ring doorbell footage, which reportedly shows Sergio Brown "taking out the trash" and having "a bonfire where he burned all her clothes."
"They said he wasn't himself the last few months. He was out of his mind," Cortez told CBS News.
Myrtle Brown was reported to be unresponsive near a creek behind her home on Saturday (September 17) while authorities were searching for her and her son, police in Maywood, Illinois announced via NBC News. The elder Brown was reported to have been killed by "multiple injures due to assault" and her death was characterized as a homicide, the Cook County Medical Examiner's Office confirmed in an email Sunday (September 17) night.
Myrtle and Sergio Brown were both reported missing on Saturday (September 16) after family members claimed they couldn't find or contact them, the Maywood Police Department said in a statement obtained by NBC Chicago. The elder Brown was located by authorities after the second round of a search launched to find the two individuals.
The police probe was characterized as a homicide investigation, however, the department's statement didn't categorize what led to that determination.
"Currently the Maywood Police Department is attempting to locate Mr. Sergio Brown," the department said.
Brown signed with the New England Patriots as an undrafted free agent in 2010 and spent his first two seasons with the franchise before signing with the Indianapolis Colts in 2012. The former Notre Dame standout spent three seasons with the Colts, as well as the 2015 season with the Jacksonville Jaguars and 2016 season with the Buffalo Bills.