Difference between "verb(past) + こと + ある" and "verb + ている"


I always translate ている as "have verb (past participle)" when refering to
resultant state.

But that current meaning can also be brought upon by past tense of verb
combined together with こと and ある.

> 彼を殺している(or ある)
>
> 彼を殺したことはある

ている here is ofcourse not the progressive one, as some verbs (die, kill, open)
do not have it.




This answer might be completely wrong but I'm writing it anyway in the hope of
learning from it.

> 彼を殺している

is simply

> I have killed him.

Whereas

> 彼を殺したことはある

sounds to me like

> I have the experience of killing him

which sounds weird, because it sounds like he can be killed multiple times.

Perhaps we could translate 彼 as boyfriend and then it would make sense as

> I have experience of killing boyfriends.

