Under Minnesota state law, an employer cannot fire, discipline, threaten, penalize, or otherwise discriminate against an employee because s/he took a reasonable amount of time off work to seek protection an order for protection for domestic abuse.
If you do need to take time off work to protect yourself or your children from domestic abuse, it is your responsibility to give your employer 48 hours' advance notice, unless you or your child are in immediate danger or unless giving notice is impractical. Your employer can ask for proof of why you are absent but s/he has to keep all information confidential.1
If your employer does violate this law, s/he can be guilty of a crime. You also have the option of bringing a civil suit for damages against your employer.2
1 MN Code § 518B.01(23)(a)
2 MN Code § 518B.01(23)(b),(c)