Text messages on Molly Matheson’s phone led police to a man they suspect strangled the 22-year-old woman in her Fort Worth, Texas, apartment near Texas Christian University in April. “I’m outside,” the first text read, according to an arrest affidavit. Another message was sent about an hour after the time they believe Matheson was killed.

“Hey. Thanks again for the advice. Its nice seeing how far you’ve come. Im proud of you brej. Hmu when you get up,” the 3 a.m. message read.

Investigators believe Reginald Kimbro, 23, sent it to cover his tracks, suggesting Matheson was alive when he left her apartment. Since detectives did not have Matheson’s PIN, they pressed her thumb against the fingerprint reader to unlock her iPhone.

Kimbro, who is charged with capital murder, has been arrested twice previously on suspicion of sexual assault but never prosecuted, according to the affidavit. Police spokesman Brad Perez said “enough evidence has been found” to prove Kimbro sexually assaulted Matheson before killing her.

“What’s really upsetting to me, why wasn’t he already behind bars? on the previous sex allegations?” Nancy Grace asked in her “Crime Stories” podcast.

Matheson’s mother found her daughter in the bathroom of her small apartment after Molly did not show up for work the next day. Investigators believe Kimbro dragged the woman into the shower in an effort to wash off evidence.

Kimbro told investigators that he briefly dated while students at the University of Arkansas. He claimed she invited him to visit her home the night she died, but that they didn’t have sex.

Nancy Grace discusses the case with Alan Duke in Friday’s “Crime Stories” episode.

[Feature Image: Handout]