love equations -- charlie eppes x reader - numb3rs

ch ;; nine

''mark herlan, 39.''

''did anyone see the shot?'' don asked terry, walking up to the scene. ''a mother and her child were witnesses, but neither heard the shot.'' terry explained. ''i'm going to pull some uniforms, see if we can find out where the shot came from.'' ciara said, turning around. charlie grabbed her arm, stopping her. ''i don't think that'll be necessary.''

''these numbers  size of the wound, angle of entry, position of the body. they already tell you what you need to know.'' charlie said, letting go of her arm. ''see, ballistic trajectories are fundamentally simple. they're the result of only two physical forces - vertical and horizontal velocity. calculating trajectories with precision requires taking into account many variables, like wind speed and direction, atmospheric pressure, temperature, humidity, inclination of gun, density of the projectile.'' he explained

 ''so I've done some rough calculations of trajectory models based on the bullet's angle of impact, wind speed and direction. i approximate that our sniper fired from right around here. this spot here. see?'' charlie asked, looking at the agent. she nodded her head. ''uh-huh.'' she confirmed. ''actually, it was more like here.'' charlie readjusted his arm, pointing up to where the shot was fired.

''ah, agent matthews!'' ciara turned around, hearing a man's voice calling out to her. ''oh, hello, uh, agent edgerton, right?'' she asked. the man nodded, holding out his hand for her to shake. ''bureau told you i was coming, right?'' he asked. ciara nodded, ''yeah, i was the one who requested you here.'' she confirmed. edgerton nodded.

''he's a sniper instructor from quantico. needed a different perspective.'' ciara explained to charlie. charlie tilted his head, looking at edgerton.  ''what makes you think he fired from your location? your location assumes he's a good shot.'' charlie said. edgerton looked at him, crossing his arms. ''i say he's just an okay shot who got lucky.'' he answered charlie.  ''what kind of empirical evidence are you basing that assumption on?''

~~''~~

''four killings... what they have in common is single shots fired from mid-caliber rifles at a distance of 200 yards or greater. however, what they don't have in common are the victims. we have a real-estate broker, a housewife, a high school student and a mailman.'' don said, briefing the agency.

''now the locations vary, the times of day vary. every-- ballistics confirms that the four bullets came from four different rifles. four shots, four kills... that kind of skill suggests a possible military background.'' ciara added to what don had explained.  edgerton cut in, ''what it suggests is that he knows his limitations enough to remain within them.'' he said rudely. ciara sighed. ''this is special agent edgerton from quantico, and he doesn't think our shooter is especially skilled.'' she said annoyed.

after a while, ciara and charlie had gone back to charlie's garage, working on the chalkboards. ''apparently there's large performance differentials between same-caliber bullets from different manufacturers.'' she read off the computer. charlie turned slightly, looking over at her. ''based on what?''

''lead composition, gunpowder packing...'' she listed. charlie nodded. ''just what I need, more variables.'' suddenly, there was knocking on the garage door, and larry had walked in. looking at ciara and charlie, he smiled at charlie. ''oh... some extra assistance in my brazen attack on the lorenz invariance?'' he joked. ciara smiled slightly. ''no, drag coefficient models.'' she said.