What else can the "Deadly Silence" mean ?
Well A deadly silence can mean something is silent and deadly, like for example "a person dying from a deadly disease (like Ebola, Cancer, etc.) or when you define "deadly silence" think of a story about deadly silent story. Well I'm not sure if you have to write a story about it.
That's all I have to say.
Samuel, the "deadly silence" has a lot of meaning, often negative however interesting to write.
I have a few sentences that may spark in your writing;
"Deadly silence", something strange, scary and often connotes negative activities brewing in the mind of a rather peaceful being. An act to conceal a deadly and inhumane aspirations towards it's target. However, "deadly silence" can also mean the shout of justice, justice that lies in the hands of people who doesn't trust the justice system anymore, people who lost hope, people who got tired of listening to false testimonies and waiting in vain for the much awaited justice. Yes, it can be regarded as "karma", some sort of belief, belief that is strengthened by that spirit and willingness to let that "deadly silence" within them.
There you have it, a few sentences from my end, I hope you follow thru and always remember to be objective in your writing.