Yes, you can expunge your record of conviction.
If you want to read the law itself, go to Oregon Revised Statute 137.225. All the information I am going to provide about how to expunge your record of conviction can be found in that law. Effective January 1, 2012, there are some changes to the law, not the least of which is that B felonies can now be set aside if the conviction and release from custody occurred more than 20 years ago. (Additionally, you must have not been arrested or arrested of any other offense after the date of the conviction sought to be set aside.)
First, your conviction must be for an offense (“offense” means violations, misdemeanors and felonies) that the law allows to be set aside. The following are crimes that cannot be set aside: (1) any traffic offenses; (2) any sex crime (sex crimes are defined in ORS 181.594(2)); (3) criminal mistreatment in the first degree under ORS 163.205 (4) endangering the welfare of a minor if it also constitutes child abuse; (5) a class A or B felony (except for a few exceptions mentioned below).
In addition, the statue to expunge record of conviction also allows to be set aside “a crime punishable as either a felony or a misdemeanor, in the discretion of the court.” This reduction of a felony to a misdemeanor applies to all C felonies but only a few A/B felonies. Under ORS 161.705 (reduction of certain felonies to misdemeanors) the following felonies may be reduced to misdemeanors at or after sentencing: delivery of marijuana under ORS 475.864, a class B felony; class B felony possession of marijuana; or the class A felony of racketeering and after successful completion of probation had the crime reduced to a misdemeanor.
In short, as long is your offense is a class C felony or lesser offense (misdemeanor or violation) and is not a traffic crime or on the above list of crimes that cannot be set aside, it is an offense that can be expunged. And, if your conviction for a B felony was more than 20 years ago, and it has been more than 20 years since you were incarcerated, and you have not been arrested or convicted for anything else since that 20-year-old conviction, then you can get a B felony set aside (with the exception of ORS 166.429, providing firearms used in a felony.
Once you have determined that you were convicted for an offense that can be set aside, three years must have elapsed since the date of conviction (not the offense date) and, you must not have been convicted for any other offense (excluding traffic violations) for a period of ten years prior to the filing a the motion to set aside the conviction.
For example, let’s say it is 2011 and you were convicted of possession of less than an ounce of marijuana (a violation) on March 12, 2002, and third degree theft in 2006. Now you want to expunge both convictions. You cannot do so because even though it has been more than three years either conviction, it has not been more than ten years since the marijuana possession conviction. Therefore, you have to wait until March 13, 2012, to file your motion to set aside the theft III conviction (because at that time ten years will have passed since the marijuana possession conviction). But you have to wait until after 2016 to expunge the marijuana conviction. Oddly, the rules allow the newer conviction to be expunged before the older one.
Finally, your right to have the court expunge your record of conviction is not absolute. The trial court has some discretion in deciding whether to allow your motion or deny it. The court may take into consideration your behavior since the conviction and may hear from the victim as to whether the conviction ought to be set aside. However, in practice it is rare for the court to even conduct a hearing as long as all the prerequisites provided for in the statute have been met and the District Attorney’s office has not filed an objection.