A Port Orange woman found dead in a home on Monday was stabbed more than 100 times and was severely beaten on the head, homicide investigators said Wednesday afternoon. 

Port Orange police also revealed they are looking for Thomas McMullen, Jr., 37, a known drug user, as the suspected killer. 

"The Port Orange Police Department is actively seeking information on the whereabouts of Thomas McMullen, 37, the suspect in the homicide of Diana Kessler," the agency said in a news release Wednesday morning. 

Port Orange police spokesman Officer Evan Doyle said Kessler, 32, had numerous knife wounds. 

"Preliminary autopsy results indicated in excess of 100 stab wounds and blunt force trauma to the victim’s head," Doyle said in a news release. "Our investigation has revealed this to be an extremely violent and prolonged event which also displayed apparent attempts to conceal the crime scene." 

The investigation also revealed that despite her relatively small size, Kessler fought for her life, Doyle said.

"The victim also displayed numerous defensive wounds on her extremities which, despite her relatively small size (5’5”, 147 lbs.), indicate an effort to defend herself against the attack," Doyle wrote in the release. 

Police believe Kessler and McMullen Jr., the suspect in her killing, were friends and there is no indication the relationship was romantic in nature, investigators said. 

"We believe that McMullen Jr. remains in the East Volusia area and is a known narcotics user, frequenting the area of International Speedway Boulevard in Daytona Beach, FL," Doyle said. 

Kessler was discovered in a home at 5939 Hatteras Drive, about 9 p.m. Monday. The home is owned by the parents of Thomas McMullen Jr., who was no longer living with his parents. 

A Port Orange police report released Wednesday indicates that the father, Thomas McMullen Sr., and his wife Linda McMullen, were out of town when Kessler's body was found in their home. A neighbor, Paul Shamp, had come to the home on Monday to feed the McMullens' cat, police said. 

Shamp found the door that would normally be left unlocked for him to feed the cat, locked. He then contacted Thomas McMullen Sr. to see if he could break into the home and when he did, he saw Kessler's body in the kitchen, investigators said. Shamp then called police. 

On Wednesday, Linda McMullen said in an email that she and her husband had kicked their son out of the home. 

"Tommy Jr. was asked to leave the house August 16th," Linda McMullen wrote. 

Thomas McMullen Jr. has a criminal record that dates back to 1999 with multiple felony charges and arrests including fraud, grand theft, forgery, and trafficking hydrocodone. 

Linda McMullen said she and her husband struggled with their son's problems and tried to help him as best they could. 

"We brought him into our home from rehab at the Phoenix House because he had nowhere to go, the last time he was out of jail he lived on the street," Linda McMullen wrote. 

The couple was vacationing in New York when Kessler's slaying occurred and they had changed the locks, she said. 

"We still do not know how he broke in the house," Linda McMullen wrote. "He came into our home and trashed it. There are cleaning crews there now trying to get blood out." 

Linda McMullen said she and her husband, a Vietnam Veteran, are being accused on social media of harboring their son. 

"Please let your readers know we are both extremely upset and the only (thing) that my husband is guilty of is trying to be a good father," wrote Linda McMullen, who was communicating as the couple was driving back home from their trip. 

"I welcomed (Kessler) into my home and gave her clothes," she wrote. "l did my very best to be kind to her as she was raising a son." 

Friends close to Kessler said her 7-year-old son is in the care of his father. 

Linda McMullen said they met Kessler through their son, but police said Kessler was not living at the house where she was killed. 

"We are extremely sorry for what Tommy Jr. has done as he has left a young child motherless," Linda McMullen said. 

Anyone with information on the whereabouts of Thomas McMullen Jr. is asked to call 386-248-1777. 

Staff writer Nancy Niles contributed to this report.