Stockton police are encouraging people to be careful when going out at night as they've noticed most of the city's unsolved homicides have a pattern. While there is no evidence of a serial killer, Stockton police Chief Stanley McFadden during a Wednesday briefing took note of online speculation of one. He also said that detectives analyzing crime data took note that some of the recent homicides have happened either during the night or early morning in poorly lit areas where there is no security camera. The victims were also alone. The Stockton Police Department said in a release that it is gathering a team of detectives, crime analysts, camera room operators, evidence technicians, and task force officers on the county, state and federal levels.