| Date of birth: | 1950 |
| Hair: | Gray |
| Eyes: | Hazel |
| Registration: | 194411 |
| Level: | Level II |
| Comments: | There is one known prior offense when Mattson was 27 years of age where he engaged in sexual intercourse with a 14 year old female. Mattson hasn't received any sexual deviancy treatment, and assessment has concluded he does have a sexual deviancy problem. |
| Arresting agency: | Walla Walla County Sheriff's Office |
| Booking location: | Walla Walla County, WA |
| Details: | In 2001 Mattson sexually assaulted four non-familial minor females between the ages of nine and twelve; two of the victims were neighbors and two resided in the same house as the suspect. Due to a plea bargain, Mattson was convicted only of Child Molestation in the 2nd degree against one victim. |
| Description: | 9A.44.086 - Child molestation in the second degree., |
| Date convicted: | Feb 5, 2002 |
| Charges: | N/A |
