There seems to be a lot of debate on the topic and I guess it's up to interpretation. It seems obvious that L's primary motivation is to solve puzzles and "win", and he's clearly willing to do unethical things and even sacrifice human lives if necessary. But do you think he cares about human life even a little bit? If so, is it on a philosophical level or does he actually feel empathy?

There are some moments that suggest he might not be completely devoid of empathy.

• referring to the dead FBI agents as 'precious lives lost', although that could be interpreted as losing an asset in solving the case

• he starts shaking and appears upset after Ukita's death, which could be interpreted in a few ways. He could feel bad about getting a team member killed, or he could just be really pissed that he's "losing". Some people have suggested he's having an autistic meltdown because Aizawa touched him, but that seems like a reach to me.

• he seemed genuinely upset for at least a split second after Watari's death (I didn't watch the dub, but in the sub the VA portrays him as losing composure for a moment)