BROWNSVILLE, Texas (ValleyCentral) — Law enforcement officials are looking for a fourth suspect connected to the fatal shooting of a teenager in Santa Rosa — asking for the public’s help in finding a man they warn poses a danger to the community.

Alberto Sanchez (Courtesy of Cameron County District Attorney’s Office)

The man, identified as Alberto Sanchez, is believed to be armed and dangerous, Cameron County District Attorney Luis V. Saenz said Friday in Brownsville. Saenz said that Sanchez is wanted on an active warrant for a charge of murder.

The district attorney spoke during press conference Friday related to a recent murder out of the Santa Rosa area, fresh off the announcement Thursday of the arrest of three men connected to the case.

“We determined these folks were all armed. These folks were all dangerous, so we determined that the U.S. Marshalls should take the lead [in this investigation] because that’s what they do,” Saenz said.

The press conference began at 1:30 p.m. Friday at the Cameron County Courthouse in Brownsville, with comments from Saenz, who was accompanied by the Western Cameron County Violent Crime Taskforce.

From left Julian Casarez and Josue Torres (Cameron County Sheriff’s Office)

It was announced Thursday that two teenagers were arrested in connection to the Jan. 26 murder of a 16-year-old in Santa Rosa. Saenz identified the victim Friday as Fernando Martinez.

Julian Casarez, 18, and Josue Torres, 17, were each charged with murder in connection to the shooting.

Last Thursday, La Feria police arrested Oscar Torres, Josue’s brother, in connection to the shooting, Saenz said. The District Attorney added that Casarez and Sanchez are cousins.

Saenz cited a potential motive for the fatal shooting as an exchange of vaping oil cartridges. Saenz said that the suspects would find out who is selling the cartridges, ask to buy them and then take the cartridges and their money, sometimes with an exchange of gunfire.

The district attorney indicated the investigation has tied the suspects to a shooting at a Whataburger in La Feria “during broad daylight.”

Saenz said the investigators would not yet disclose the caliber used in the Santa Rosa killing because local officials are working jointly with the Bureau of Alcohol, Tobacco, Firearms and Explosives.