The accurate and reliable detection of unintended emissions from radio receivers has a broad range of commercial and security applications. This paper presents and analyzes Hurst parameter-based detection method for super-regenerative receivers (SRRs). SRRs are low cost, easily manipulated, and widely used in common remote devices including doorbells, garage door openers, and remote controlled (R/C) toys. By design the SRR is a passive device that should only receive an RF signal. However, it also emits a low power, unintended electromagnetic signal. Such unintended emissions are enhanced by the presence of a known stimulating signal. Also, the emission is referred to as a device signature since it can uniquely identify the devices. The proposed detection method exploits a self-similarity property of such emissions to distinguish it from background noise. Hurst parameter quantifies the self-similarity. It is employed to detect and identify the SRR-based devices even if the signal fades into a noise.