HOUSTON (KTRK) -- Less than 24 hours after a 22-year-old man was shot and killed outside a Midtown bar, two teenagers - 15 and 16 years old - were arrested for his murder.Juan Carlos Ramirez was leaving F Bar after midnight Thursday morning when he was assaulted by two suspects. He tried to fight them off, holding on to his keys. Moment later he lay dead, not far from where his Ford truck had been parked. The robbers-turned-killers stole it.Overnight, Houston police tracked down the suspects in southeast Houston. Outside, investigators say the Ford truck was found, along with items taken from a woman that was with Ramirez. Police say the juveniles confessed to the robbery and shooting.It was the second carjacking in Midtown that same night. In the other, a couple fended off a robbery attempt by driving away; however, the robber fired a shot into the car, striking the driver. He's recovering in a hospital.Not far from Midtown, a group of demonstrators stood at the corner of Montrose and Westheimer, with signs denouncing crime and calling for more police protection. The fatal carjacking was the impetus for the rally against crime.Take Back Montrose, as it was called, was the idea of Brad Janacek, who says Montrose has been going through a wave of crimes, ranging from break-ins, robberies, including car hackings and assaults."We like HPD," he told us. "We're tired of crime and we need more protection, we're upset about it."Harris County Constable Alan Rosen says he'll been sending tactical units into the area to spot problems before they start."We'll work in concert with HPD and we just won't be here for a few days," Rosen said.Looking at the group inviting law enforcement in, Rosen said, "it's great to see a community taking the first step. It takes all of us to solve crime, together."