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Convicted Felon Arrested for May Murder
September 18, 2026
A man who was released from prison last year is behind bars again after he killed a man earlier this year.


On Sunday, May 17, District 1 patrol officers responded to a shooting at a home on Mayfair Road near Beach Boulevard. They found 28-year-old Jarrius Brown with a gunshot wound. He was rushed to a local hospital but did not survive his injuries.

Jacksonville Sheriff's Office (JSO) Homicide Unit detectives got to work. Their investigation revealed Brown was in a fight with 35-year-old Mark Mulliens that afternoon. The fight escalated, leading Mulliens to shoot Brown before running off.

Detectives used all the investigative tools available, including surveillance camera video and witness statements to build a case to arrest Mulliens for Brown’s murder.

Mulliens is a convicted felon who served four prison sentences for drug trafficking and armed robbery convictions. Using that, detectives arrested him 10 days after the shooting for Possession of a Firearm by a Convicted Felon as they built the murder case against him. He’s been in the John E. Goode Pretrial Detention Facility (Duval County jail) on that charge since May. On Wednesday, September 17, 2026, detectives arrested him for Brown’s murder.

To view the post regarding this arrest on JSO's social media platforms, please click on one of the following links: Facebook Instagram
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