They had to kill him, before he hacked into their computer system.
Yes, in proper English.
"The bear wandered down a few hallways and into a computer room"
Hey Where's Conspiracy Guy this morning?
Actually, in correct accepted English, all animals are referred to as "it." Only our sentimentality toward pets, and perhaps more recently the PETA mentality, has pushed us toward saying "he" or "she" with animals.
Since English is largely a gender-neutral language, he and she are traditionally reserved for humans only.
In 60's vernacular, "Pig kills pig." (my apologies to all of you fine public resvants out there, nothing personal)
or
In trucker lingo, "Bear kills bear."