This is interesting. Especially the part about Iowa, since some think Abby and Libby's case might be connected to Lizzie and Lyric's case.
Within nine years of Virginia's establishment of the first state DNA databank, the other forty-nine states passed laws requiring the collection of DNA samples from certain criminals for the purposes of establishing state DNA databanks. All fifty states require DNA samples from convicted sex offenders, with some states collecting from all classes of felons, as well as certain classes of misdemeanants. Additionally, the FBI estimates that most states will eventually begin to collect DNA from all convicted felons when the cost of collecting and analyzing DNA decreases.
Four states require DNA samples from all convicted felons, violent or non-violent, which means, for example, that in New Mexico an individual convicted of felony speeding will have his or her DNA profile included in the state databank. Additionally, at least eight states require the collection of blood from certain classes of convicted misdemeanants, and until 1997 South Dakota's DNA databasing law allowed the collection of samples from persons merely arrested for a crime. Under a Louisiana law effective September 1, 1999, law enforcement officials will collect DNA samples from adults and juveniles arrested for sex offenses or certain violent felonies.
Under Texas law, if an individual was previously convicted of a sex offense, or of burglary with the intent to commit a sex offense, then that individual is required to submit a DNA sample to the state databank upon subsequent conviction for "any offense," which could include non-violent felonies or misdemeanors.
Iowa is the only state that has not statutorily promulgated rules for which convicted felons and misdemeanants shall be included in the state DNA databank, but instead the Iowa law provides that the state's attorney general shall adopt such rules. When making the determination, the Iowa Attorney General shall consider a number of factors, including the "deterrent effect of DNA profiling, the likelihood of repeated violations, and the seriousness of the offense." Additionally, Iowa law allows a sentencing court to determine whether a defendant who will be placed on probation or work release must submit DNA to the state databank. Like the attorney general, the sentencing court must make the determination based on the defendant's personal history and criminal record, "the deterrent effect of DNA profiling, the likelihood of repeated violations by the defendant, and the seriousness of the offense." This provision of the Iowa law also provides that courts shall order DNA profiling "when funds have been allocated from the general fund of the state, or funds are provided by other public or private sources."
http://www.pbs.org/wgbh/pages/frontline/shows/case/revolution/databases.html