There are several publicly available resources that share the number of murders in New Jersey by year within crime reports filled with statistics, including those provided by local, state, and federal law enforcement agencies, as well as Project: Cold Case and the Murder Accountability Project. For example, the Uniform Crime Reports are released every year by the Federal Bureau of Investigation, which are often filled with interesting statistics regarding the sorts of crimes committed with their respective crime rates in every state.
Another valuable resource is Project: Cold Case who, in partnership with the Murder Accountability Project, has created a webpage that shows the number of unsolved homicides in each state along with their respective homicide clearance rate. According to this page, from 1980 to 2019 there were approximately 21,224 murders in New Jersey alone. Surprisingly, around 14,678 of those murders have been solved through the years, leaving the state with around 6,546 unsolved murders in New Jersey.
Among many of the cases listed on various law enforcement websites and other public databases or lists are some of the many unsolved murders in northern New Jersey, including the 1992 murder of Renae McLoed, the 2013 murder of Chrismely Hidalgo, the 2014 murder of Jermaine Gamble, and the 1990 murder of Maria Acevedo, among many others. Others on these lists which are frequently included are the various unsolved central New Jersey murders, including the 1977 murder of George Drumm, the 2016 murder of Norman Mosely, the 1994 murder of Jennifer Persia, and the 1994 murder of Joseph Tomasino II, along with several others. Lastly, a couple of the unsolved murders in Trenton, New Jersey, which can also be found within different databases or on various law enforcement websites include the the 2013 murder of Cornelius Boakai and the 2012 murder of Joshua Moore, in addition to a couple of unsolved murders in Mercer County, New Jersey, which include the the 1984 murder of Donna Macho and the 2014 murder of Joyce Vanderhoff.