Whether a manslaughter case can be sealed in Colorado depends on how it ended.
A Manslaughter Conviction
A manslaughter conviction cannot be sealed under C.R.S. 24-72-706, which governs sealing of conviction records. Subsection (2)(a)(VI)(H) excludes sentencing for a felony crime enumerated in C.R.S. 24-4.1-302(1), and that list includes manslaughter.
A Case That Did Not End in a Conviction
Records of a case that ended without a conviction are sealed under C.R.S. 24-72-705. The court shall order them sealed on its own motion when the case is completely dismissed, when the defendant is acquitted of all counts, or when the defendant completes a diversion agreement or a deferred judgment and all counts are dismissed.
Manslaughter adds one step. Because it is a crime listed in 24-4.1-302(1), subsection (1)(d) requires the court to allow the district attorney the opportunity to inform the victim that the record will be sealed. If the victim objects, the court sets a return date no later than thirty-five days after receipt of the motion; if there is no objection within thirty-five days after the motion is filed, the court shall grant it. If the sealing does not happen automatically, subsection (2) allows the defendant to file a written motion to seal at any time after the dismissal or acquittal, without being charged fees or costs.