They're at crimes minutes after they happen.
Now investigators want people to see what they see. Baltimore police's forensics team is giving people an inside look at how investigators analyze crime scenes.
The methods are faster, the technology more efficient, and the demand for experienced personnel is higher than ever.
As medics and other first responders get to a scene, a forensics crew follows.
"Slowing things down and, as you would say if you were in athletics, keeping your head on a swivel. You want to make sure that you pay attention to detail," Steve O'Dell, the head of forensics at BPD, said.
The 16-year vet says the 39 civilian employees in the department's crime scene sciences division have the tough task of analyzing nearly 15,000 scenes a year, minutes after they happen.
"It's the detailed, the attention to detail, approach that everybody has to keep in mind while understanding that there are calls holding, there are other things going on, there are limited resources," O'Dell said.
That attention to detail is why the department is offering a three week, $1200 course for anyone interested in how it all works.
From fingerprinting, to photography, and documenting blood splatter -- the rush course is an entry into the world of forensics.
"So when we put this on a crime scene, this will recreate the area. So if we set it up in this room like so, then this head will spin 360 degrees and it'll recreate the area," Thomas Wisner, a crime scene investigator, said referring to using the Leica 360 laser scanner.
Using it is part of one of the lessons throughout the course.