Luis Fernando Lopez
Luis Fernando Lopez is a Dominican-American street gangster associated with the Northwood Dominican Drug Dealers and also works as a bodyguard for club owner and Ancelotti associate Anthony "Gay Tony" Prince. He is also be rumored to be involved in underground fight clubs. Luis appears during Grand Theft Auto IV on three occasions. The first time he visits the Bank of Liberty branch in Algonquin during the bank robbery pulled off by the McReary brothers and Niko Bellic in the mission Three Leaf Clover. Fellow hostage Eugene Reaper suggested that they stand up to the robbers. Luis stated it was a bad idea, which was proven when Eugene killed Keane and was then shot dead by Packie and Derrick. Luis escaped unharmed when the surviving robbers fled the scene. The second time, he ambushes the diamond deal that Niko was making with Isaac Roth on behalf of the Pegorinos in the mission Museum Piece. It could be assumed, after the events in Lost & Damned, that Luis' employer has sent him to retrieve the diamonds after The Lost ambush the first exchange at The Platypus, killing Gay Tony in the process. It has also been speculated that Luis worked with Johnny, but he was there with the Ancelotti Family when the deal crashed, and he shot at Johnny. Furthermore, during the end credits, one recap of the museum scenario shows Luis trying to escape via the roof as Johnny and Niko escape by bike and car respectively. Luis dashes to a skylight, then begins to open fire at someone below. The third time he went to the diamond/Gracie Ancelotti exchange with Gay Tony in the mission Diamonds Are a Girl's Best Friend.
Luis appears in The Lost and Damned twice, once in the mission Diamonds in the Rough when Johnny is stealing the diamonds from Gay Tony, and during the museum mission. He told Gay Tony's hired hand to flee with the diamonds in a limo, while Luis dealt with the other bikers, with Johnny in hot pursuit of the diamonds. It is presumed Luis killed all minor-bikers.
Also when Johnny plants the wire-tap into Bryce Dawkins Infernus (which later becomes Niko's) you are able to call a certain number to listen to the wiretap. Bernie Crane mentions Gay Tony, and then mentions Luis saying "If he played for our team I would totally be the catcher."
There is some speculation he will be the protagonist in the second episode of the DLC. Reasons to support this are his mysterious appearances in Grand Theft Auto IV, and questionable background. This is also suspected due to Niko and Johnny, two protagonists, meet up in the museum, and Luis appears to ambush it. As well as the achievement you get after completing the Museum Piece mission is called "Impossible Trinity", which at first is cryptic, but makes speculative sense: 3 characters have been brought together by almost impossible events.Additionally,all of the GTA IV era protagonists have been arrested for highjacking,which is indeed a law Lopez has broken.