Lisa Kutis of the Goodyear Police Department said detectives are continuing to look for Helen Jean Lee, who was reported missing Wednesday, but "have not ruled out that this may be a homicide investigation."
Kutis said Jason Howell, Lee's grandson, is considered a "person of interest" in his grandmother's disappearance.
People who knew Howell said he had a troubled past. One neighbor said he knew Howell had a bad temper.
ABC15 spoke to his former employer at Palm Valley Golf Club who said Howell was fired back in January for sending "belligerent" racist text messages to minority employees.
Howell had been staying with Lee, 78, at her home in Goodyear. Another neighbor said he felt Lee was "frustrated over the years with his behavior."
Howell was taken into custody on Wednesday after allegedly stealing a car left running outside Kyrene Del Cielo with a 12-year-old girl inside. The girl was able to get out of the car before Howell drove away.
As he fled police, Howell allegedly rammed at least two police cars. The chase ended with Howell's arrest at Future City Park near 50th Street and Ray Road.
According to court documents Howell admitted to being drunk and high on meth that night.
Those same papers label him as "a suspect in an active murder investigation," and his bail was set at $300,000.
While in custody for the carjacking, Howell gave detectives more information that lead them just west of Gila Bend.
"What was initially believed to be and set to look like that of a concealed body in the area has turned out to be additional evidence to the case… but not a body," said Kutis.
ABC15 on Thursday morning was outside Lee's home near McDowell and Litchfield roads, where the garage door could be seen smashed in as police tape surrounded the property. During a search of the home, detectives reportedly found evidence that indicates foul play.
Neighbors told ABC15 Lee's husband passed away several years ago. Police said her grandson Howell was living with Lee at the West Valley home.
Neighbors said they became worried after Lee missed her regular church meeting on Tuesday night.
"Obviously if we haven't heard from her, the church hasn't heard from her, cell phone's turned off, it's pretty ominous in my opinion," neighbor Don Morrison said
Police say they'll continue searching in hopes of finding Lee but they're also focused now on finding a body and even more evidence.