I'm looking for a word for a murder of a co-conspirator or witness in order to preclude testimony to the authorities.
Many suspect that Fat Tony's apparent fatal accident on the New Jersey Turnpike was in fact a [word] perpetrated by other members of the Soho Heist team.
Update I know the verb to silence, and I was hoping for a snappy noun for, basically, "killing to silence." An ad hoc construction becomes unwieldy in my actual usage, which deals with statistics. Perhaps here's a more relevant example:
According the police, 98 homicides can be traced directly to the crackdown. Only seven resulted from police shootings in the line of duty; the rest were [word] by the crime syndicates themselves.