YPSILANTI, Mich. -- The autopsy results were released Thursday in the murder of 29-year-old Lindsay Graygo of Ypsilanti Township.

The Washtenaw County Sheriff's Department said Graygo died by strangulation.

She was sexually assaulted, and there was a struggle.

Graygo was found dead face down in the bathtub in her apartment bathroom Tuesday night.

Graygo lived in the Lake Shore apartment complex off Grove Road.

Deputies received a call from Lindsay Anne Graygo's co-workers to check her well-being around 5:15 p.m. on Tuesday after she did not show up for work.

Police said they believe Graygo willingly let her killer into her home because there was no sign of forced entry.

"In the initial observation, things seemed peculiar," said Washtenaw County Sheriff Dan Minzy.

Minzy said they are frustrated because they do not have any leads at this time.

Investigators are reviewing Graygo's phone records and interviewing people who knew her.

Deputies said they do not have any suspects at this time.

Graygo recently moved from Erie Pennsylvania to Ypsilanti take a job at Splash Mountain in Dundee.

Anyone with information is asked to call the Washtenaw County Sheriff's tip line at 734-973-7711 or Crime Stoppers at 1-800-SPEAKUP.