The apartment along South Avenue in Secane was in disarray when police arrived Wednesday afternoon: Blood and feces were on the floor, ripped-up papers were strewn about, and a message was written on a wall.

In the bathroom, authorities found the naked body of Markia Benson, 36, in a bathtub full of water.

Police in Upper Darby Township have ruled Benson's death a homicide, and on Thursday announced they were still searching for her killer, whom they believe Benson knew.

But whoever did it, Upper Darby Police Superintendent Mike Chitwood said at a news conference, "meant to hurt her, embarrass her, and harm her."

Benson had several injuries to the head, neck, and face, consistent with stab wounds or even strangulation.

On a wall in her apartment, writing that "left a clear message" was scrawled. Chitwood declined to say what it said.

No "glaring" signs of sexual abuse were evident, said David Madonna, captain of Upper Darby criminal investigations.

Neighbors described Benson as "very, very quiet," Chitwood said.

After she didn't show up for work at a packaging company in Chester, a coworker and a friend separately went to the New Orleans Park apartments in the 900 block of South Avenue to check on her.

They contacted the apartment's management and gained entry into her unit about 4:45 p.m. and found her in the bathtub, Chitwood said.

Benson was last seen in public about 8 p.m. Tuesday, Chitwood said, getting out of her car near the apartment complex. On Wednesday morning around 8, she sent a few text messages to her mother.

Police believe she was slain between 9 and 10 a.m.

Police found no evidence of forced entry at the apartment.

Benson had no estranged husband or children, he said, but "there are other people in her life" whom investigators are "checking out."

"Her killer was very, very angry," Chitwood said. "A senseless, sadistic murder."