Social proof, an element of social influence, may be an effective memory aid for eyewitness recall in investigative interviews. The current study examined the effect of social proof on eyewitness recall (with and without a memory recall technique, Report Everything). Participants (N = 128) viewed a verbal altercation on video and then recalled their memory of the event in an interview. Participants were assigned randomly to one of four conditions: Control, Social Proof, Report Everything, or Social Proof + Report Everything. Conditions with either the Social Proof or Report Everything techniques produced longer talking times than those without. Conditions with Report Everything elicited the most investigation relevant information from participants. Results indicated small benefits for using Social Proof and large benefits for using Report Everything to improve witness recall. Further research is needed to determine the best combination of interviewing techniques to increase eyewitnesses' memory recall of investigation relevant information.