It sounds like what you need is a bit of solo play.

You're trying to turn your character into the villain of an ongoing mystery side-quest, based on the fact that he goes around murdering people during downtime. Okay. You want to play out the "murdering people during downtime" part. Cool. You don't want your fellow players to react to the inevitable metagame knowledge. Cool.

So why are you doing it in front of them?

You don't need codes (potentially suspicious). You don't need note-passing (always suspicious). Any time you're in front of the rest of the party, you wouldn't be doing this stuff anyway. You just need to get together with the DM outside of the scheduled group times (possibly handled via chat, phone, email, or whatever) and run through the murder scenes (perhaps in a somewhat abbreviated manner). Then the next time the party convenes, the DM talks about the horrible murders that occurred when everyone was on downtime. They'll almost certainly investigate in-character (its an obvious plot hook, after all) but that's what you want, right?

It's been a few years, but I did once run a campaign (of heavily modified D&D 2nd edition) that involved a significant amount of meeting separately with specific players in ones or twos to run personalized scenes and then pulling them back together for the group events. It required a fairly heavy DM investment (something I had time for at the time) and it meant that the party never really gelled as a group, but it worked quite well at allowing differences in player knowledge, and sometimes-antagonistic interactions. Your case is a much more limited scope. In your case, I would expect that it might lead to some emotional separation in your mind between you and the rest of the party (which, honestly, seems appropriate given what you've said) and some additional effort on the part of your DM (but not an overwhelming amount). If the DM is not willing to make the additional investment, this technique is not for you. If they are, though, I believe it woudl work well for you.

It sounds like what you need is a bit of solo play.

You're trying to turn your character into the villain of an ongoing mystery side-quest, based on the fact that he goes around murdering people during downtime. Okay. You want to play out the "murdering people during downtime" part. Cool. You don't want your fellow players to react to the inevitable metagame knowledge. Cool.

So why are you doing it in front of them?

You don't need codes (potentially suspicious). You don't need note-passing (always suspicious). Any time you're in front of the rest of the party, you wouldn't be doing this stuff anyway. You just need to get together with the DM outside of the scheduled group times (possibly handled via chat, phone, email, or whatever) and run through the murder scenes (perhaps in a somewhat abbreviated manner). Then the next time the party convenes, the DM talks about the horrible murders that occurred when everyone was on downtime. They'll almost certainly investigate in-character (its an obvious plot hook, after all) but that's what you want, right?

It's been a few years, but I did once run a campaign (of heavily modified D&D 2nd edition) that involved a significant amount of meeting separately with specific players in ones or twos to run personalized scenes and then pulling them back together for the group events. It required a fairly heavy DM investment (something I had time for at the time) and it meant that the party never really gelled as a group, but it worked quite well at allowing differences in player knowledge, and sometimes-antagonistic interactions. Your case is a much more limited scope. In your case, I would expect that it might lead to some emotional separation in your mind between you and the rest of the party (which, honestly, seems appropriate given what you've said) and some additional effort on the part of your DM (but not an overwhelming amount). If the DM is not willing to make the additional investment, this technique is not for you. If they are, though, I believe it would work well for you.

It sounds like what you need is a bit of solo play.

You're trying to turn your character into the villain of an ongoing mystery side-quest, based on the fact that he goes around murdering people during downtime. Okay. You want to play out the "murdering people during downtime" part. Cool. You don't want your fellow players to react to the inevitable metagame knowledge. Cool.

So why are you doing it in front of them?

You don't need codes (potentially suspicious). You don't need note-passing (always suspicious). Any time you're in front of the rest of the party, you wouldn't be doing this stuff anyway. You just need to get together with the DM outside of the scheduled group times (possibly handled via chat, phone, email, or whatever) and run through the murder scenes (perhaps in a somewhat abbreviated manner). Then the next time the party convenes, the DM talks about the horrible murders that occurred when everyone was on downtime. They'll almost certainly investigate in-character (its an obvious plot hook, after all) but that's what you want, right?

It sounds like what you need is a bit of solo play.

You're trying to turn your character into the villain of an ongoing mystery side-quest, based on the fact that he goes around murdering people during downtime. Okay. You want to play out the "murdering people during downtime" part. Cool. You don't want your fellow players to react to the inevitable metagame knowledge. Cool.

So why are you doing it in front of them?

You don't need codes (potentially suspicious). You don't need note-passing (always suspicious). Any time you're in front of the rest of the party, you wouldn't be doing this stuff anyway. You just need to get together with the DM outside of the scheduled group times (possibly handled via chat, phone, email, or whatever) and run through the murder scenes (perhaps in a somewhat abbreviated manner). Then the next time the party convenes, the DM talks about the horrible murders that occurred when everyone was on downtime. They'll almost certainly investigate in-character (its an obvious plot hook, after all) but that's what you want, right?

It's been a few years, but I did once run a campaign (of heavily modified D&D 2nd edition) that involved a significant amount of meeting separately with specific players in ones or twos to run personalized scenes and then pulling them back together for the group events. It required a fairly heavy DM investment (something I had time for at the time) and it meant that the party never really gelled as a group, but it worked quite well at allowing differences in player knowledge, and sometimes-antagonistic interactions. Your case is a much more limited scope. In your case, I would expect that it might lead to some emotional separation in your mind between you and the rest of the party (which, honestly, seems appropriate given what you've said) and some additional effort on the part of your DM (but not an overwhelming amount). If the DM is not willing to make the additional investment, this technique is not for you. If they are, though, I believe it woudl work well for you.