A 35-year- old Sioux Falls man is behind bars accused of assaulting his girlfriend and her six children on numerous occasions over the past year; including threatening to kill them all. 

Court papers say Mark Cowels punched, stomped and strangled the victim and her children at two separate homes between August of last year and September of this year. 

Cowels is charged with six counts of cruelty to a minor and one count of aggravated assault choking. 

The court papers say Cowels allegedly threatened to kill the children if they told their mother about the beatings, showing them his gun.  

In one of the incidents, he allegedly strangled one of the children with a vacuum cord. 

If convicted on all counts, Cowels faces a maximum penalty of 90 years in prison.  He’s being held in jail on $25,000 cash only bond.