Stat Loss
From UO Lost Lands Wiki
A murderer which has 5 or more short term murders, will receive a skill and stat penalty of 9-20% upon resurrection. This effect is permanent.
The penalty only applies when the character is resurrected, so it is possible to wait for kill counts to decay before resurrecting, in order to receive no penalty.
To determine whether or not your character is in stat loss, you can use the "I must consider my sins" command. If you are in stat loss, the returned message will be "If thou should return to the land of the living, the innocent shall wreak havoc upon thy soul."