Generally, a felony's res gestae is considered terminated when the suspect has achieved a position of relative safety from law enforcement.
Statements that could be admitted into evidence as res gestae fall into three headings: The present sense impression, excited utterance, and then-existing mental, emotional, or physical condition hearsay exceptions, respective to the above headings, now cover many situations under the Federal Rules of Evidence that would formerly have been considered res gestae.
[4] The common law res gestae exception has been preserved under the statutory hearsay regime in s118(4) of the Criminal Justice Act 2003.
In 1997, the Law Commission argued that the primary use of it was to allow evidence from unavailable witnesses (including those who were deceased or in fear of testifying)—their proposal for a hearsay exception for this specific reason became section 116 of the Criminal Justice Act 2003.
Given the existence of this, "it is difficult to see what useful purpose was served by retaining this group of exceptions to the hearsay rule, because they add little if anything to what is already provided by section 116" argues Professor JR Spencer.