them. Ecological contamination hypothesis states: environment taints perceptions. Those who are in dangerous neighborhood seem more dangerous (ex: police use more force in poverty-stricken neighborhoods that have high crime rates and greater proportions of minorities). When the background appeared to be safe, racial bias was present (armed Blacks were shot quicker and more frequently than armed whites), vs. when the background was threatening, racial bias was reduced (demonstrated by a tendency to increase the rate at which White targets were shot increasing). Blacks were still treated hostilely in both dangerous and nondangerous contexts. Dangerous contexts proved to reduce racial bias in the decision to shoot in that Whites were treated in a similar, hostile fashion to Blacks, not that Blacks were treated with similar regard or restraint as Whites. There is an increasing racial bias from white people, racially ambiguous individuals, and Black faces. Racially ambiguous faces get more racial bias than white faces and less racial bias than black faces, acting as an intermediate, on average. In a white-only context, racially ambiguous individuals are viewed as more prototypically Black, whereas in a Black-only context, racially ambiguous individuals are viewed as less prototypically black. Perceptions of racially ambiguous faces can be impacted by direct-racial labeling and the context in which the faces are presented (White only vs Black only environments). Mixed contexts lead to a more mild bias than segregated situation. Signal detection theory (SDT) involves a bias and reduces ability to distinguish tools from weapons after a Black prime even in situations when race was incidental (nondiagnostic). The only cue the participants were obligated to attend to was the presence of a weapon or non-weapon. However, unable to sever blacks from their stereotype and its related factors, unjust heightened threat perception persists. Strategies for change The bias toward threat perception evaluation of black people, caused by stereotypes, can be lessened with access to diagnostic cues (ex: presence or absence of a weapon) and motivation. Lay people are more racially biased, on average, than trained police officers. Target prototypicality is shown to moderate racial bias. Police officers show a reduced racial bias in comparison to members of the community, however, police officers were no better than community members in their sensitivity to prototypic targets. Exposing people to stimuli where race is unrelated to the stereotype may eliminate racial bias. Initial responses were racially biased but research shows that extensive practice