Police arrest 22-year-old suspect in strangling of art student

A suspect has been arrested in the death of an art school student, who was found strangled in Philadelphia last fall, police said.

The Philadelphia Police Department confirmed to ABC News this morning that David Grier, 22, is under arrest for the killing of Kierra Johnson, a 21-year-old student at the Hussian School of Art.

Philadelphia Police Capt. John Ryan told reporters at a press conference this afternoon that Johnson was with Grier when she was last seen on Nov. 2, 2017. Ryan said the pair, who police believe were acquaintances, were spotted on surveillance video by the Southeastern Pennsylvania Transportation Authority.

Johnson's body was found lying facedown in Cobbs Creek in West Philadelphia the following morning, after her family had reported her missing. Investigators later determined she had been strangled to death.

Investigators now believe the suspect sexually assaulted Johnson before killing her. Grier was taken into custody Wednesday afternoon, according to Ryan.

"We believe it to be sexual in nature," the police captain said of the potential motive for the crime. "David Grier did not comment."

Grier apparently has a criminal past. He was on parole after being charged in 2016 for attempted murder in Oakland, California, according to ABC's Philadelphia station WPVI.

Hussian School of Art described Johnson, or "Ki, as she was known to all," as an "honors student" and an "excellent artist," according to a statement given to WPVI in November.

The college did not immediately respond to ABC News' request for comment today.

In 2015, as an intern for the National Park Service's Mass Parks Student Career Intake Program, Johnson wrote a brief essay about how growing up as an inner city kid fueled her duel passion for art and nature.

"Art is what kept me on the right track since I felt I didn't have much access to nature," she wrote. "Being an artist and growing up in [a] lower class home with a single parent I have learned to use the resources I have to create bigger and better things and so I do not feel the need to separate my passion for art and my passion for conservation."