Thank you for your patience. Here are the statutes themselves, with the offenses in bold for you to see:
609.495 AIDING AN OFFENDER.
Subdivision 1.Definition of crime.
(a) Whoever harbors, conceals, aids, or assists by word or acts another whom the actor knows or has reason to know has committed a crime under the laws of this or another state or of the United States with intent that such offender shall avoid or escape from arrest, trial, conviction, or punishment, may be sentenced to imprisonment for not more than three years or to payment of a fine of not more than $5,000, or both if the crime committed or attempted by the other person is a felony.
(b) Whoever knowingly harbors, conceals, or aids a person who is on probation, parole, or supervised release because of a felony level conviction and for whom an arrest and detention order has been issued, with intent that the person evade or escape being taken into custody under the order, may be sentenced to imprisonment for not more than three years or to payment of a fine of not more than $5,000, or both. As used in this paragraph, "arrest and detention order" means a written order to take and detain a probationer, parolee, or supervised releasee that is issued under section 243.05, subdivision 1; 244.19, subdivision 4; or 401.02, subdivision 4.
Whoever intentionally aids another person whom the actor knows or has reason to know has committed a criminal act, by destroying or concealing evidence of that crime, providing false or misleading information about that crime, receiving the proceeds of that crime, or otherwise obstructing the investigation or prosecution of that crime is an accomplice after the fact and may be sentenced to not more than one-half of the statutory maximum sentence of imprisonment or to payment of a fine of not more than one-half of the maximum fine that could be imposed on the principal offender for the crime of violence. For purposes of this subdivision, "criminal act" means an act that is a crime listed in section 609.11, subdivision 9, under the laws of this or another state, or of the United States, and also includes an act that would be a criminal act if committed by an adult.
Subd. 4.Taking responsibility for criminal acts.
(a) Unless the person is convicted of the underlying crime, a person who assumes responsibility for a criminal act with the intent to obstruct, impede, or prevent a criminal investigation may be sentenced to not more than one-half of the statutory maximum sentence of imprisonment or to payment of a fine of not more than one-half of the maximum fine that could be imposed on the principal offender for the criminal act.
(b) Nothing in this subdivision shall be construed to impair the right of any individual or group to engage in speech protected by the United States Constitution or the Minnesota Constitution.
An offense committed under subdivision 1 or 3 may be prosecuted in:
(1) the county where the aiding or obstructing behavior occurred; or
(2) the county where the underlying criminal act occurred.
As I am not sure which assault your friend was charged under (Minnesota has 5 degrees of assault), I will post the most serious one for your review:
609.221 ASSAULT IN THE FIRST DEGREE.
Subdivision 1.Great bodily harm.
Whoever assaults another and inflicts great bodily harm may be sentenced to imprisonment for not more than 20 years or to payment of a fine of not more than $30,000, or both.
Subd. 2.Use of deadly force against peace officer or correctional employee.
(a) Whoever assaults a peace officer or correctional employee by using or attempting to use deadly force against the officer or employee while the officer or employee is engaged in the performance of a duty imposed by law, policy, or rule may be sentenced to imprisonment for not more than 20 years or to payment of a fine of not more than $30,000, or both.
(b) A person convicted of assaulting a peace officer or correctional employee as described in paragraph (a) shall be committed to the commissioner of corrections for not less than ten years, nor more than 20 years. A defendant convicted and sentenced as required by this paragraph is not eligible for probation, parole, discharge, work release, or supervised release, until that person has served the full term of imprisonment as provided by law, notwithstanding the provisions of sections 241.26, 242.19, 243.05, 244.04, 609.12, and 609.135. Notwithstanding section 609.135, the court may not stay the imposition or execution of this sentence.
(c) As used in this subdivision:
(1) "correctional employee" means an employee of a public or private prison, jail, or workhouse;
(2) "deadly force" has the meaning given in section 609.066, subdivision 1; and
(3) "peace officer" has the meaning given in section 626.84, subdivision 1.