Sioux City police arrested two people following a bank robbery there Monday. 17-year-old Mikalla Walker was arrested in Sioux City and charged with first degree robbery. 20-year-old Jonathan Van Tuyl was arrested in Omaha on two warrants unrelated to the robbery. Sioux City police sergeant Lisa Claeys says they were able to arrest Walker about 90 minutes after the robbery.She says Walker and others helped police find Van Tuyl.Claeys says they believe Van Tuyl actually robbed the bank while Walker waited in the get away car. Van Tuyl is still in custody in Nebraska and will be charged with robbery upon his return to Iowa. The robbery was the third in Sioux City in the last ten days.