Historical risk assessment forms for a sample of 173 males with a history of violent offending and under supervision by Merseyside Youth Offending Services (YOS) were investigated. Subsequent arrest records were scrutinised in order to obtain a better understanding of the relationship of social and psychological risk factors to offending behavior. The mean age of the sample at the point of contact with YOS was 16.01 (SD = 1.37) with a range between 12 and 18 years. Assault was associated with solo expressive offending, a history of domestic violence, low school attendance and an inability to control impulsivity and aggression. Robbery was associated instrumental and escalated violent offending, psychological disorders, and deviant groups, including family criminal involvement. Risk assessments by professionals and the young people indicated that substance misuse co-occurred with robbery. The findings suggest that solo offenders commit the majority of violent offences and that targeted interventions should distinguish between expressive and instrumental offending.

对 173 名有暴力犯罪历史并接受默西塞德青少年犯罪服务中心 (YOS) 监督的男性样本进行了历史风险评估表的调查。随后对逮捕记录进行了审查，以便更好地了解社会和心理风险因素与犯罪行为的关系。与 YOS 接触点的样本平均年龄为 16.01 岁 ( SD = 1.37)，范围在 12 至 18 岁之间。攻击行为与单独表达性犯罪、家庭暴力史、入学率低以及无法控制冲动和攻击性有关。抢劫与工具性和升级的暴力犯罪、心理障碍和异常群体（包括家庭犯罪参与）有关。专业人士和年轻人的风险评估表明，药物滥用与抢劫同时发生。研究结果表明，大多数暴力犯罪都是单独犯罪者实施的，有针对性的干预措施应区分表现性犯罪和工具性犯罪。