There is a problem with the warp drive when the manifolds refuse to fire up due to a problem in EPS Conduit 141. It turns out the problem is because Ensign Suder hid the murdered body of Crewman Darwin there in the hope that the remains would be vapourised.

Torres discovers the remains of Crewman Darwin

It is possible to order the ship's computer to seal private quarters. Tuvok does this, placing a Level 1 security seal on his own quarters before ordering the computer to delete security clearance Tuvok 1494-Lambda.

A coil spanner is part of engineering equipment, and obviously enough to deliver a killing blow as Suder used one to kill Darwin.

Under Starfleet Directive 101, Suder does not have to answer any questions while he is a suspect in the murder.

A sweepstake for the purpose of gambling is considered by the senior officers to be unsuitable activity for the crew of a Starfleet vessel. Possibly, that is, if winning profit is involved. The First Officer, who closes down Paris' sweepstake in [Meld] is happy enough with the baby pool set up among the crew to try and guess the birth time of Tom and B'Elanna's daughter [#171 and #172 Endgame].