The man suspected of killing five people at the Cascade Mall in September engaged in abusive behavior toward his girlfriend, according to documents released Thursday by the Skagit County police.

The documents contain the transcript of an interview police conducted with the ex-girlfriend of Arcan Cetin, the man who allegedly carried out the September 23 mass shooting at the Macy's in Burlington

Cetin's 22-year-old ex-girlfriend now lives in Spanaway. She said she met Cetin while working at the commissary on NAS Whidbey.

The ex-girlfriend told detectives that she once worked at Macy's, though it's unclear whether she worked at the Burlington location when she and Cetin were dating. More recently, she worked at a Macy's in Pierce County.

She said the store's insistence that she work one Thanksgiving while they were dating made Cetin very angry.

The woman told police that her mother was supposed to cook the holiday meal that year but became ill and needed to go to the emergency room. That left Cetin's ex-girlfriend to cook the family meal and then work on the holiday.

“... so I made all the food…and then they open a day before, so I worked the whole entire day before until, like 3 a.m. the next day. Yeah I know it was horrible, and so he brought me food.”

She told detectives they dated for nine months, and during that time he would have fits of rage that he would take out on her or his family.

One night, she said she and Cetin’s step-father were talking about politics, “and he, um, thought his dad was looking at me the wrong way ... and he attacked his dad.”

“He literally ... lunges at him and started punching him as hard as he could,” she told detectives.

Court records revealed that Cetin has a criminal record for domestic violence, and that his stepfather was the victim. His ex-girlfriend said Cetin refused to complete the court-ordered psychiatric evaluations.

The ex-girlfriend said Cetin was controlling and grabbed her so hard he left bruises. She finally broke up with him after he brutally assaulted her while they were having sex. She said it was after New Year’s Day in 2015.

After their breakup, she claimed Cetin told her he once committed beastiality before they began dating. She said he’d shown her text messages and described encounters to her that led her to believe it was true.

She also claimed Cetin threatened to rape and kill her after she broke off their relationship. He stalked her using social media apps but she kept blocking him she said, adding that she never called police.

The investigative documents also reveal that immediately after the shootings, Cetin drove to Seattle and visited the Space Needle where he ate a salmon meal. He later slept in his car.

He also told detectives they would find ISIS references on his computer and that he followed ISIS on the news.

One detective wrote a brief narrative of an interview with Pamela Eagan, whose husband was one of the victims who died. She told detectives she fell and hit her head as her husband ran. She hid underneath a clothing rack and could see what she believed to be the suspect’s feet as he walked by. She said she heard a foreign language being spoken, “her first guess was that it was a Middle Eastern language but she was not sure.”

In addition, the documents say that Cetin went to the movie theater at the Cascade Mall before he went to Macy's. At 6:22 p.m. he reportedly bought a ticket to the movie 'Snowden'. It's believed he used his cell phone to prop open an outside door of the theater, and then briefly left.

Theater staff told investigators someone found the phone, turned it in, and closed the door that had been propped open. Not long after that, Cetin returned. Detectives said he can be seen on surveillance video, asking theater staff if anyone found a phone. They gave it back to him.

Less than thirty minutes later, came the gunfire at Macy's -- which sits just across the parking lot from the theater.

Cetin remains in the Skagit County Jail awaiting trial.