I am a RN and plead guilty to DV Harassment 7/2011.
I completed 1 year of probation.
I have been hired in a new position as a RN since this conviction.
Now I am applying for another position. I was asked to agree to a
Criminal background check and asked to disclose any misdemeanor or
Felony convictions. I was in fact truthful and provided complete disclosure
Of the conviction.
Are there any laws to protect me as this was a result of an argument
Between me and my asstranged husband at the time.
Are there any known algorythms of how an employer determines
Hirability of a person with such a conviction.
The conviction was in Westminster, Colorado, Adams County.

No, there are none. There's the licensing board of each state first, to determine if you keep your license or not, and after that it's up to each employer. Nurses are in demand, and given the nature of your conviction, you should be able to find work. Whether this employer will hire you or not is anybody's guess. It may have as much to with how long you stay in one job and what references you get from employers as the record.

Normally if there are domestic violence charges, most health care providers will not hire. If they were aware of this up front and still hired you, you will be OK, since they know all the facts.