The cop mispoke and said remains....whoops. Poor girl, whoever she is. RIP. The friend also said he liked to meet girls on the bus....so theres a clue.
Go to his FB page and read through the comments for more clarity.
Usually when they charge an individual, once arrested, if more charges, they like to wait until they know what all the charges will be so they can do it all at once. They are most likely waiting for the autopsy, to charge with murder, and then the bomb and whatever else he may get charged with. Right now they only have evidence of what he did to the body.