Eyewitness testimony is notoriously unreliable. In fact, studies have shown that eyewitnesses are wrong about 25% of the time. This is due to a number of factors, including:

* Memory distortion: Eyewitnesses' memories of events can be distorted by a number of factors, such as stress, time, and suggestion.

* Contextual information: Eyewitnesses may be influenced by the context in which they saw an event, such as the presence or absence of weapons or the race or gender of the suspect.

* Weapon focus: Eyewitnesses may focus on the weapon used in a crime, rather than the perpetrator's face.

* Change of appearance: A suspect's appearance may have changed since the crime was committed, making it difficult for an eyewitness to identify them.

For all of these reasons, eyewitness testimony should not be used as the sole basis for convicting someone of a crime.