Per 
SCP-3546 Decontaminated
Item #: SCP-3546
Object Class: Safe Euclid
Special Containment Procedures: SCP-3546 is contained in a standard 25 square meter containment chamber. The object is stored inside a level 3 keycard-locked secure opaque case attached on a 1 m concrete pedestal in the centre of its cell. Security clearance level 3 is required to access SCP-3546's cell itself. Access is prohibited by any and all personnel without the mentioned security clearance level or higher. See below: SCP-3546's containment chamber location (Security clearance level 3 credentials or higher).
The following data is protected as sensitive information:
Description: SCP-3546 is an anomalous object with unusual properties and capabilities. SCP-3546 is a
'U.S. M1917 Trench Knife', a combat knife developed by the U.S. Military for use in the first world war. The object, however, does not possess the properties that one would expect such an item to have. The trench knife specialises in stabbing people to cause injury or death in trench warfare, as opposed to slashing, evident by SCP-3546 Decontaminated (image). SCP-3546 is unable to pierce human skin, except as detailed in Revision 3546-1.
No single test to date has shown that SCP-3546 can pierce the skin of any human being. As of yet, how the entity manages to repel itself from penetrating when up to 56 kilonewtons of force is applied to the knife is unknown. See Test 3546-7. The object appears to be very sharp, and is indeed able to cause pain to anyone who presses against the tip, observed as proportional to the force applied, however the skin of the subject will never be broken. SCP-3546 acts as if it were a regular knife when cutting or stabbing objects or other living organisms.
SCP-3546 is now classified as Euclid after Revision 3546-1, based on a more dangerous property possessed by about the entity. See Test 3546-15. Subjects who touch the blade of SCP-3546 will become 'infected' by the entity, and will be killed (presumably by SCP-3546) at the next available opportunity, that is, when there is nobody to witness the subject's death. Subjects who touch the blade when alone (no direct observation/recording) will die immediately. There have been no methods found as of yet to avoid the fate that is suffered by subjects coming in contact with SCP-3546, however inevitable death can be prolonged with constant observation, as SCP-3546 can never be seen murdering/victims can never be seen dying. Any persons killed by SCP-3546 will be found with one stab wound directly through their heart. Blood containing DNA of the victims of SCP-3546 is always present on the blade of the object after the victim has been killed.
If the blade is not decontaminated, following the outlined Cleaning Procedures, SCP-3546 will start to kill the closest DNA relatives of its victims. Starting with siblings, then parents, and so on until the DNA traces on its blade are removed. SCP-3546 does not appear to ever move from its containment chamber, and it is as of yet unknown how it manages to kill people when no experiments could ever force it to stab anyone. No methods of containment have been able to prevent the death of people who have left their DNA traces on the blade of SCP-3546.
Wether or not SCP-3546 murders its victims, or if its victims merely die as a result of their interaction with SCP-3546, is unclear.
Revision 3546-1:
Object Class determined as Euclid due to the ever present potential that the location of SCP-3546 may be ever be unknown. This object class designation is based on the likelihood that SCP-3546 moves to kill its victims. Such an event as SCP-3546 not returning to its cell after any experiment involving it killing anyone could be catastrophic based on the murdering capability of SCP-3546. SCP-3546 appears to select a home, currently in its containment chamber. SCP-3546 will always return here after it has killed, assuming it moves at all, the idea that it could ever 're-materialise' anywhere else where the blade is unable to be decontaminated could result in the exponential deaths of relatives of any person who's DNA was tested on SCP-3546, hence the stricter Object Class designation.
Cleaning Procedures: The goal of the decontamination/cleaning of the blade of SCP-3546 is to remove all DNA and blood traces from the object, without coming in contact with the object. It is a prohibited action for Class-A and Class-B personnel.
Equip high durability latex gloves. Rinse only the blade of SCP-3546 with deionised water, and apply
6M NaOCl. Keep hands well away from the blade, then allow the object to sit in its case. Insert security level 3 keycard into case and press the 'dry' button.
No personnel with low enough personnel classification to be able to decontaminate SCP-3546 should posses level 3 security clearance, so one guard one researcher with access should authorise and oversee the operation, and use their keycard as required to enter the cell and open the case.
