Background: The Crisis intervention program is very crucial to reduce the violence of emergency and acute mental illness. In the present research, an adjusted violence scale instrument through the implementation of a crisis intervention program that was combined with antipsychotic medicine was proposed for acute mental illness patients. Methods and Material: The Brøset’s violence risk scale instrument was utilized to measure the patients' behavior with intervention; after that, it was refined (mixed method with concurrent embedded strategy) to adapt the measuring scales. Each patient was given a crisis intervention program and received similar antipsychotic medication that comprised of Chlorpromazine 300 mg/day, Haloperidol 15 mg/day, and Trihexyphenidyl 6 mg/day; then, the response was recorded for 7 to 12 days in an acute inpatient psychiatric unit. The instrument was adjusted to satisfy the changes in patients' behaviors throughout an intervention. Then, a trial procedure, verification, and validation were performed on the content of the instrument. Results: The results revealed that a paired-samples t-test comparison of the panic level of 72 patients' violence was t=-7617 and probability 0.000. The proportion of agreement Cohen's kappa (κ) can range from -1 to +1. It means that the kappa (κ) equal to 0.667 represents a moderate agreement. Furthermore, since Probability was very low ( P < 0.05). Conclusions: It can be concluded that there was different levels of patients' violence before and after the crisis intervention. The interrater statistical results confirmed that the majority of nurses had similar perceptions towards items of modified Brøset’s violence risk scales.