A 24-year-old Jacksonville man has been arrested in the murder of a 45-year-old passenger who was shot while riding in a car on the city's Westside back in January, nearly nine months before detectives finally made an arrest this week. Dominque Alexander now faces charges of murder, four counts of attempted murder, and possession of a firearm by a convicted felon in connection with the death of Porfirio Rosario.
According to the Jacksonville Sheriff's Office
, District 4 Patrol officers responded on Jan. 28 to a shooting near 103rd Street and Britton Lane. Rosario was a passenger in a car when he was shot, and the driver rushed him to a local hospital, where he died from his gunshot wound shortly after arriving, the agency said.
Investigators say Alexander was driving a separate vehicle and opened fire on the car carrying Rosario. Immediately after the shooting, homicide detectives began speaking with witnesses and canvassing the area as they worked to identify a suspect, ultimately naming Alexander in connection with Rosario's death.
A Felon Already Behind Bars
Alexander was not a free man for most of the time between the shooting and his murder arrest. The sheriff's office said he had already been arrested in March on a charge of possession of a firearm by a convicted felon and was being held in the Duval County Jail awaiting trial on that case while the homicide investigation continued.
That changed this week, when the sheriff's office said it received a warrant for Alexander's arrest in the murder case on Wednesday, October 21, 2026. Detectives then arrested him for murder, four counts of attempted murder, and possession of a firearm by a convicted felon, the agency said in its announcement. The gun charge echoes the standard laid out in Florida Statute 790.23, which makes it unlawful for certain people, including convicted felons, to own, possess, or carry a firearm under specified circumstances.
In announcing the arrest, the sheriff's office framed it as a message about the persistence of its homicide unit. “No matter how many minutes, hours, days or months pass, we will seek justice,” the agency said in its post, adding, “This week, our Homicide detectives arrested a 24-year-old man for Murder after he shot another man at the beginning of the year.”
Part of a Broader Shift in Jacksonville's Homicide Numbers
The arrest comes against the backdrop of a notable decline in killings across Jacksonville in recent years. The city recorded an unofficial 84 homicides in 2024, its lowest total since 2011, when 86 people were killed, according to Jacksonville.com. That 2024 figure marked a 47% decrease from the 159 homicides tallied in 2023, ending a 12-year stretch in which the city had topped 100 homicide victims annually.
Anyone with information about the January shooting is asked to contact Jacksonville police at 904-630-0500. The sheriff's office has not released additional details about a motive, the weapon used, or the circumstances behind the four attempted murder counts tied to the case.
