Ex-NFL Player Sergio Brown Is Still Missing Days After His Mother Was Found Dead: Everything We Know So Far

The search for ex-NFL player Sergio Brown continued Wednesday, as police in Illinois attempted to locate the former professional athlete four days after his mother was found dead.

Family members reported Brown, 35, and his mother, Myrtle, 73, missing on Saturday, after they told police in Maywood, Ill. that they were unable to contact either of them.

Authorities quickly found Myrtle's body in a creek behind her home in the Chicago suburb – and officials consider her death a homicide.

Meanwhile, one of Myrtle's neighbors has said he saw Sergio burning his mother's clothes and acting "out of his mind" just before he disappeared.

And in recent days, Sergio has posted a string of cryptic videos on Instagram, including one where he called his mother's death "fake news."

"FBI had to do it, they got the power to do some s--- like that," Sergio says in one of the clips. "What the f--- is going on? That is fake news. Don't come f---ing with me."

Here's what we know about the case so far:

Sergio Brown And His Mother Were Reported Missing on Saturday

Relatives of Sergio and Myrtle contacted Maywood police on Saturday after they said they were unable to get a hold of either of them.

Myrtle's sister, Sheila Simmons, told WGN-TV she last heard from her sister on Thursday.

Myrtle Brown was Found Dead – And Officials Say Her Death is a Homicide

Authorities filed missing person reports for both Sergio and Myrtle Saturday and began a search effort, Maywood police said.

"Upon conducting a second and wider search of the area, Myrtle Brown was discovered unresponsive near a creek to the rear of her residence," police said in a news release.

Myrtle's body was brought to the Cook County Medical Examiner's Office, where officials determined she died of "multiple injuries due to assault." They classified her death as a homicide.

“We’re going to find out what happened because it’s not normal for my sister to not answer her phone, not to respond to text messages," Simmons told WGN News. "People have been reaching out to her since Friday. No one was able to reach her.

“Now I got the call this morning saying that she’s missing, so immediately I came out here and find out my sister is dead.”

Police said they were searching for Sergio and asked anyone with information about his whereabouts to call detectives at 708 368-4131 or the anonymous tip line at 708 450-1787.

Sergio's Brother Pleaded for the Former Athlete to Come Home

In a post on Instagram on Sunday, Sergio's brother, Nick Brown, penned a tribute to their mother and pleaded for his brother to "come home."

"It's a sad but hopeful time and we will all get through this together," Nick wrote. "Mom always told me, 'tough times don’t last' and our last conversation about tough times being temporary is my beacon of hope."

He went on to thank his mother for "being so strong, caring, diligent, fancy, funny and for saving my art."

"I won't let you down."

Nick also wrote that Sergio was still missing.

"If anyone knows where he is I want him to know that I love you and please come home."

In Instagram Videos, Sergio Appears to Rant About His Mother's Murder and Mock Police

Since Monday, Sergio has posted several videos from on the Instagram account, @intplayerwithapassport, he appears to have been using while on the lam.

In one posted on Monday, he says he thought his mother was on vacation and calls what happened to her "fake news." He also claims the FBI visited his house and that authorities kidnapped him from his home, twice.

"FBI had to do it, they got the power to do some s--- like that. What the f--- is going on? That is fake news," Sergio says. "Don't come f---ing with me."

A second video, posted Tuesday, Sergio can be seen quoting the Disney movie, "Finding Nemo," repeating its popular line, "Just keep swimming."

Sergio appeared in a third video on Wednesday, rapping lyrics to the song, "Legend," by Canadian rapper Drake.

A video earlier this week that has since been removed reportedly showed Sergio with a location tag for Mexico City, Mexico. The Nemo clip was tagged as coming from the Sydney Opera House, which is near where the fictional children's movie takes place.

Wednesday's video was tagged as being in his hometown, Maywood, Ill., although palm trees can be seen behind on the street behind Sergio.

Maywood police said Tuesday investigators were aware of at least the video where Sergio makes his "fake news" claims.

"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 police spokesperson said in a statement.

"Currently this is an active investigation, and the department is unable to share any further details at this time."

The spokesperson did not respond to questions from The Messenger about the case on Wednesday.

A Neighbor Says Sergio Brown was 'Out of His Mind' Before Went Missing

Sergio's neighbor told WBBM earlier this week the former football player did not seem like himself and burned his mother's clothes before he disappeared.

Carlos Cortez, who lives near Myrtle's home and said he last saw the Browns on Thursday, told the outlet he provided police with footage collected by his security video camera.

“They seen him taking out the trash, and they seen him have a bonfire where he burned all her clothes,” Cortez said.

He said Sergio's behavior in the footage appears to be in line with what relatives have told him about the former football player.

“They said he wasn’t himself the past few months," Cortez said. "He was out of his mind."

Prior to joining the NFL, Sergio played football at Proviso East High School in Maywood and at Notre Dame.

He signed with the New England Patriots in 2010 as an undrafted free agent and went on to play six seasons with multiple teams before his retirement in 2016.