So who are they then?

Couple arrested in underweight boy’s death face murder charges

'26-year-old Jon Phillips and 21-year-old Sarah Berry were advised of the charges they face in court. The charges are first degree murder after deliberation and child abuse resulting in death knowingly and recklessly.

Neither Phillips nor Berry spoke during Wednesday's court appearance. Both will be in jail until charges are officially filed.

A member of Phillips' family tells 9NEWS she is in shock.

Denver Police discovered the body of the boy, who has not yet been identified, at a residence located in the 3300 block of South Tamarac Street on Sunday.

Authorities were dispatched to the residence at about 3 p.m. on a report that a child was suffering cardiac arrest.

Police sources tell 9NEWS the boy weighed only about 30 pounds and appeared severely malnourished.

Authorities say he was transported to Swedish Medical Center where he was pronounced dead at about 3:45 p.m.

It is not clear how Berry or Phillips were related to the child, if at all, but sources tell 9NEWS they are not his biological parents.

The couple is now in custody, although charges have yet to be filed.

The Department of Human Services says a younger sibling was taken out of the home and placed in protective custody. The child will then be put in foster care.'