Cold case investigations have revealed that, in many cases, the offenders are responsible for multiple crimes. Therefore, prioritizing cold case investigations can assist in both resolving crimes and preventing future ones.
Estimates vary, but one estimate of the number of serial killers in the United States who have never been prosecuted for their crimes was as high as 2,000. Another study suggests that up to 15% of homicides are the result of serial killers. Meanwhile, estimates of the number of victims of serial killers, from a research study out of Indiana University-Purdue University Indianapolis, range from fewer than 200 to almost 2,000 each year. The study notes that quantifying the estimated number of victims is difficult, and generalizing and extrapolating data has created a wide range of estimates — but even the low end of the range is alarming.
NIJ had several robust programs that have helped law enforcement agencies solve cold cases over the years. (Recently, nonresearch support for cold case investigations was transferred to one of NIJ’s sister agencies, the Bureau of Justice Assistance.) In the process, NIJ-sponsored research has discovered a number of important connections between cold cases and serial offenders, the most alarming of whom are serial killers.
There is a whole section on cold case serial killers that starts at page 31 here:
https://www.ojp.gov/pdffiles1/nij/252722.pdf
a few times. I wonder if LE will find images of children?
to Websleuths 
