Joseph Jones arrested for killing Shavon Phillips

Joseph Foster Jones.

WATCH: ABC7's Hatzel Vela talks with Shavon Phillips' mother and father.

A 31-year-old Capitol Heights man was arrested for killing a woman whose remains were discovered in a bag in a Fort Washington creek in August.

Prince George’s County Police arrested Joseph Jones on Friday in connection with the slaying of 21-year-old Shavon Phillips of D.C.

Tonight, investigators say - according to cell phone records - Jones picked up Phillips with the intention of taking her to a Fredericksburg car auction to buy a car.

"We believe she was carrying $3,800 in cash at the time she disappeared," says Major Mike Straughan of the Prince George's County Police.

Investigators say Jones killed Phillips because he wanted her money.

Police tracked Jones' cell phone, and it showed he drove to Fort Washington. They say he then dumped her body in the creek.

Phillips was last seen on Monday, July 30 leaving from a daycare center in the 400 block of 61st Street in Northeast D.C.

Investigators say her body was found inside a duffel bag in a creek in Ft. Washington the next day.

Her family says Phillips had just finished nursing school and had a new job lined up. They say she adored her 2-year-old daughter, so it made no sense to them when Phillips dropped off her daughter at daycare Monday morning and never returned.