SALEM – Two men police say were responsible for the gang related shooting death of an 18-year-old outside a Bennett Street restaurant two months ago remain held without bail, after pleading innocent.Bonrad Sok, 17, of 103 Warren St., #1, and Kevin Keo, 16, of 21 Morris St., pleaded not guilty Friday in Salem Superior Court to the premeditated first-degree murder of Cristian Vargas-Martinez.It was about 5 p.m., on Nov. 1 when Vargas-Martinez, 18, of 153 Chatham St., Lynn, was gunned down outside the Golden Lake Restaurant at 38 Bennett St.Authorities believe Sok and a group confronted Vargas-Martinez and his girlfriend in the parking lot where a fight ensued.When Vargas-Martinez ran back into the restaurant, the fight continued, but was stopped.In the meantime, Sok apparently recruited Keo and he reportedly showed up with a .22 caliber handgun.When Vargas-Martinez went outside, Sok allegedly fired a single bullet, striking Vargas-Martinez in the chest.Sok surrendered himself to police shortly after the incident. Keo was arrested following an investigation.Authorities say that Keo and Sok are members of the “Blood Gangster” gang and Vargas-Martinez is apparently affiliated with the “Asian Street Walkers.”Police believe the incident may have been in retaliation from a previous altercation.Police have yet to find the weapon used, according to Assistant District Attorney James B. Gubitose, who is prosecuting the case for the commonwealth.Sok is being held in custody at the Middleton Jail while Keo is held at the Plymouth House of Corrections.Their next scheduled court appearance is set down for Feb. 21.A conviction on the charge will put them in state prison for the rest of their lives, with no chance of ever being paroled.A third alleged participant, Moses Pen, 19, of 21 Norton St., Lynn, was arraigned earlier on a charge of being an accessory to the fact of murder for sheltering Keo in his bedroom for a few days following the incident.