The fallibility of memory has been often demonstrated. A plethora of studies has focused on external influences that can affect memory reports, such as suggestive questioning. Adopting different paradigms (e.g., misinformation, memory conformity), the recurrent pattern of findings of these studies is that suggestion can make people prone to falsely recall details that were never experienced (i.e., commission errors, false details). In addition, suggestion can make them unable to recall truly experienced events or event-related details. However, internal influences can also affect memory. One such internal influence is deception. In the last decade, several studies have investigated how memory can be affected by deception. Specifically, these studies have shown that a person who has intentionally deceived the listener about an experienced event, subsequently when the person comes forward with the truth shows an impaired memory for such an event. This line of research examined the detrimental effects on memory by taking into account different strategies to deceive (e.g., false denials, feigned amnesia, and fabrication) and found that the memory outcomes due to deception can vary based on the strategy used to deceive. A number of studies has also demonstrated that another type of deception - known as self-deception - can influence our memory. This strategy relies on the act of deceiving our own selves and seems to reduce the recall of negative memories. The understanding of the effects of external (e.g., suggestion) and internal (e.g., deception, self-deception) on memory is important, not only in order to gain more fundamental information on how memory works, but also because of the relevance of memory functioning within the legal context. Memory distortions, for example, inaccurate eyewitness testimony, can lead to impactful legal decisions, such as wrongful convictions. Several studies have underlined the harmful consequences of distorted statements. Additional support is found in databases from various worldwide associations who strive to obtain fair justice for people involved in wrongful convictions cases (for instance, www.innocenceproject.org). Therefore, it is important that researchers continue to provide evidence on the mnemonic impact of internal and external factors that influence legal practitioners to help avoid miscarriages of justice.