The 27-year-old man accused of shooting four people during a fight outside a Denver staffing office Monday morning has been arrested, police say.Joshua Grays is being investigated for attempted murder charges for the shooting that left one person in critical condition and hurt three others outside a LaborMax office near Leetsdale Drive and Quebec Street.The shooting happened just before 6 a.m. Monday.LaborMax is a staffing agency where people can go to be placed for temporary jobs. A man Denver7 spoke to at the scene, Kevin Delgado, said tensions rose after job-seekers were told there were no more available jobs for the day."All I heard was, 'No more tickets, no more nothing,'" he said. "Shut the door, close it, lock it, and that was it."Delgado said he saw a man arguing with a woman behind the counter about a job ticket he wasn't getting. Three others were trying to de-escalate the situation before shots rang out. Delgado said as many as 10 rounds were fired in a chaotic scene. He said he helped tend to the victims after the suspect ran. Grays was found later Monday in Greenwood Village, police said.Delgado said a lot of ex-convicts go to LaborMax offices looking for work. He said Mondays altercation is a result of a growing issue in a tight employment market.[Its] been happening a lot more in these offices that I've seen in Aurora, here, Lakewood these [offices] have caused a lot of scenes where guys get violent, he said. An ex-offender like me that comes from prison, we don't know anything else besides violence. 4 people shot near Leetsdale Drive and Quebec Street Monday: DPD