Authorities concluded red fluid on a blood-spattered shirt, which was dropped off at a dry cleaner by the father-in-law of a Texas woman murdered inside a church, was not from the victim. The man, Randy Bevers took the shirts to a Midlothian dry cleaner four days after the April 18 murder of Terri "Missy" Bevers. Terri Bevers was found dead inside the Creekside Church in Midlothian, about six miles away from the dry cleaner.

Terri Bevers was slain as she was getting ready to lead a 5 a.m. fitness class, reports CBS DFW. When her students began to arrive at the church that morning, they found her unresponsive and called 911, police said. Bevers died from a head wound, according to a police records.

A person seen in surveillance video wearing what appears to be police body armor broke into the church before she arrived, according to police. Her suspected assailant also was seen on surveillance video walking the hallways of the church early that morning, using a hammer to break windows, while wearing a helmet and tactical gear.

Bevers' wounds were "consistent with tools the suspect was carrying throughout the building," documents stated.

She was a 45-year-old mother of three.

Recent tests confirmed the blood on the shirts in question is animal, which supports the father-in-law's claim the blood was from the family dog. Randy Bevers told CBS DFW the blood came from their pet dog, Kilo, who was killed in a fight with another dog at a relative's house, where and his wife have been staying since the murder. He said the shirts belonging to both him and his wife were stained with the animal's blood when they took the dying animal to the Animal Emergency Hospital of Mansfield.

Police have not said if they have suspects in the case, although they previously indicated that there was a list of persons of interest.  Midlothian Chief of Police Carl Smith said the invader was "designed to look like a police officer," reports NBCDFW. They had not determined whether the attacker was male or female.

"We really believe that somebody knows who this person is," Midlothian Assistant Chief of Police Kevin Johnson said at a press conference.

Bevers led the fitness initiative referred to as Gladiator Camp.

Texas Rangers also joined the investigation, as well as did the FBI, U.S. Marshals, and the Bureau of Alcohol, Tobacco, Firearms and Explosives.

The motive behind the attack remains unclear.

Mark Garcia, who worked out with Terri Bevers regularly at a nearby gym, told CBS News she seemed a little more reserved in the weeks prior to the murder. "I don't think she was at the wrong place at the wrong time. I feel like someone was after her," said Garcia.