त्रिरात्रादूर्ध्वमग्राह्यः शङ्कितकः पृच्छाभावादन्यत्रोपकरणदर्शनात् ॥ कZ_०४.८.०५ ॥
trirātrād ūrdhvam agrāhyaḥ śaṅkitakaḥ pṛcchābhāvād anyatra-upakaraṇa-darśanāt
A mere suspect should not be detained beyond three nights—when there is no further basis for questioning and when the implements/evidence are seen elsewhere (i.e., not connected to him).
Time-bounded custody: suspicion must quickly mature into evidence-based inquiry, otherwise the state must release the person to prevent abuse.