Brain's prefrontal cortex doesn't fully develop until your 20s.

人脑的前额皮质要到二十多岁才会发育完全
Means your teen years are spent

意味着人在青少年时期
oblivious to consequences and prone to reckless behavior.

更为鲁莽冲动不计后果
Our killer's about 15 years too late for that excuse.

凶手要想用这个当借口恐怕晚了十五年
Well, you think a decade and a half

你以为15年就能
would let everyone grow into mature and caring adults.

让所有人都变得成熟友善吗
Not always the case.

我看未必
Well, no visible blood on any of the sharp implements.

利器上都没有明显血迹
I'll bring them back to the lab anyways.

不过我还是得把它们都带回实验室
Got a bloody handprint in the bubble tray.

吹泡机上有个血手印
No ridge detail.

掌纹不明显
Killer may have wiped their hands in the soap.

凶手可能用肥皂水洗了手