Are all killers serial killers?

[The Entity]

So ive done the tutorial murder all good. and since then there have been four other murder cases, each and every one is a serial murder.

is this normal or am i just very (un) lucky?

[Sky Wizard]

this is normal. a killer will continue to kill until you catch them.

[Cooperal]

Yes. The world only ever has one killer at a time. You will never see two different killers working in parallel. All murders will be from the same murderer until they are caught.

[Klax]

Once you pop you just can't stop.