This study examined the amount of force used by and against law enforcement officers and more than 50 characteristics of officers, civilians, and arrest situations associated with the use of different levels of force. An important component of this multijurisdiction project was to employ a common measurement of elements of force and predictors of force. Data were gathered about suspects' and police officers' behaviors from adult custody arrests in six urban law enforcement agencies. The participating agencies were the Charlotte-Mecklenburg (North Carolina) Police Department, Colorado Springs (Colorado) Police Department, Dallas (Texas) Police Department, St. Petersburg (Florida) Police Department, San Diego (California) Police Department, and San Diego County (California) Sheriff's Department. Data collection began at different times in the participating departments, so the total sample included arrests during the summer, fall, and winter of 1996-1997. Forms were completed and coded for 7,512 adult custody arrests (Part 1). This form was used to record officer self-reports on the characteristics of the arrest situation, the suspects, and the officers, and the specific behavioral acts of officers, suspects, and bystanders in a particular arrest. Similar items were asked of 1,156 suspects interviewed in local jails at the time they were booked following arrest to obtain an independent assessment of officer and suspect use of force (Part 2). Officers were informed that some suspects would be interviewed, but they did not know which would be interviewed or when. Using the items included on the police survey, the research team constructed four measures of force used by police officers -- physical force, physical force plus threats, continuum of force, and maximum force. Four comparable measures of force used by arrested suspects were also developed. These measures are included in the data for Part 1. Each measure was derived by combining specific actions by law enforcement officers or by suspects in various ways. The first measure was a traditional conceptual dichotomy of arrests in which physical force was or was not used. For both the police and for suspects, the definition of physical force included any arrest in which a weapon or weaponless tactic was used. In addition, police arrests in which officers used a severe restraint were included. The second measure, physical force plus threats, was similar to physical force but added the use of threats and displays of weapons. To address the potential limitations of these two dichotomous measures, two other measures were developed. The continuum-of-force measure captured the levels of force commonly used in official policies by the participating law enforcement agencies. To construct the fourth measure, maximum force, 503 experienced officers in five of the six jurisdictions ranked a variety of hypothetical types of force by officers and by suspects on a scale from 1 (least forceful) to 100 (most forceful). Officers were asked to rank these items based on their own personal experience, not official policy. These rankings of police and suspect use of force, which appear in Part 3, were averaged for each jurisdiction and used in Part 1 to weight the behaviors that occurred in the sampled arrests. Variables for Parts 1 and 2 include nature of the arrest, features of the arrest location, mobilization of the police, and officer and suspect characteristics. Part 3 provides officer rankings on 54 items that suspects might do or say during an arrest. Separately, officers ranked a series of 44 items that a police officer might do or say during an arrest. These items include spitting, shouting or cursing, hitting, wrestling, pushing, resisting, fleeing, commanding, using conversational voice, and using pressure point holds, as well as possession, display, threat of use, or use of several weapons (e.g., knife, chemical agent, dog, blunt object, handgun, motor vehicle).