The Static-99 uses a similar method to the Risk Matrix 2000; the two have one author in common (David Thornton). An updated scoring system was produced in 2002/3, which tries to take additional factors into account, including reduction in risk because of offence-free time (ie, risk less if no recent offences known). In practice, many of the recommendations made in connection with this scoring are not supported by empirical research. In other words, there is a large element of the authors' opinion in the scoring scheme, and we still await scientific evidence on how good the authors' opinion actually is. As with the Risk Matrix 2000, the Static-99 uses items relating to age, victim, and offence history.

Problems with the Static-99
  1. It doesn’t take age into account after 25; Wollert (2006) showed this seriously exaggerates risk in older offenders.
  2. Revised scoring rules have introduced confusion over how some things should be scored; the effect is to increase error.
  3. Other problems are similar to RM 2000 (which it greatly resembles).