I have looked evil square in the eyes more times than I can count. I have also seen the results of those evil individuals actions many times, it never gets easy.
The worst was a parolee who beat his girlfriend so bad I thought for sure she was dead and that the bubbles coming through the blood on her face was her life leaving her. Miraculously, she held on long enough to make it to a trauma center and was then airlifted to University Hospitals in Cleveland. She made it after a few weeks of touch and go.
My sergeant and I (the responding and investigating officers) didn't need much to send him back to prison. He went back for the rest of his 12 1/2 years and was convicted to do another 12. Hopefully he stays there and can never hurt anyone again. I will never forget how he chuckled when I asked him why he had blood on his knuckles as I was handcuffing him.
Domestic calls really are the absolute worst. The tenant next door said that it sounded like someone was dropping a dumbell on the floor, it was him pounding her head on the floor.