Mathew Patrick Tunks tried to clean up his girlfriend's blood with a towel and then phoned a friend.

``It's Mathew,'' he said.

``I need you to do me a really, really big favour.

``I need you to come and pick me up. 

``I'm at the Penny Royal, I've just killed Jessica.''

Tunks, 39, pleaded guilty yesterday to murdering his de facto partner Jessica Ann Kupsch by punching and kicking her head in a room at Launceston's Penny Royal Motel on August 9.

The Rocherlea man had been in what he described as an on-off relationship with 29-year-old Miss Kupsch for six years, and the pair had a child together last year.

In a video interview played in the Supreme Court in Launceston yesterday, Tunks told police he had not meant to kill Miss Kupsch.

He had booked the hotel to ``do something special'' for her, and intended to take her out for dinner.

It was supposed to be a romantic night.

It ended in murder.

Tunks told police that he and Miss Kupsch had spent the previous night together at Rocherlea before separating the next morning - Miss Kupsch to her mother's house to see her three eldest children and he to a sporting goods store to pick up a new pair of adidas sneakers on lay-by.

They kept in contact via text message and arranged to meet again in the Office Works car park in Bathurst Street about 12.30pm.

``In one of the texts I said I had picked up my new runners, and Jess said: `Oh, it must be nice to buy something for yourself,' '' he told police.

``And I thought, `Yeah, it did feel good.'

``So out of that I thought, `OK, I'll take her out for a good night.' 

``Shout her tea, nice room, do something nice for her.''

Tunks said he had drunk about 12 cans of premixed bourbon and taken 10 Valium tablets and five Temazepam by 3pm, when they booked into the Penny Royal.

They inspected the room before booking and at Miss Kupsch's instigation, requested a late checkout.

Tunks said they continued drinking in the room until about 5pm, when they went to Target to buy Miss Kupsch a new outfit to wear to dinner that night.

Tunks got into a fight with two men on the way back from Target, near the Galaxy Hotel.

He met Miss Kupsch again outside Irish Murphy's Hotel and they walked back to the Penny Royal, where he took between 10 and 20 more Valium and continued drinking as she dyed her hair.

About 9pm, they had an argument.

``I can't remember what the argument was over now, something about the kid,'' Tunks said.

``Jessica turned and said something smug to me, and after that I lost it, I just . . . I assaulted her.''

Tunks told police he punched Miss Kupsch once to the side of the head, causing her to fall to the floor unconscious.

He said he then kicked her twice to the face and once to the arm as she lay on the ground, but later admitted to police that it could have been more.

Pathologist Donald Ritchie said Miss Kupsch had ``very extensive, very severe injuries'' and had been hit or kicked at least 12 times.

``They are the kind of injuries that you see in people who have been in motor vehicle accidents,'' Dr Ritchie said.

A bruise on her chest showed an imprint of the sneakers Tunks had picked up that day.

After the attack, Tunks said he waited to see if Miss Kupsch would wake up, and then checked her pulse.

He didn't call an ambulance.

Instead, Tunks grabbed one of the wet towels that Miss Kupsch had used to dye her hair and wiped blood off the mirror, dragged her body nearer the bed and then called his friend.

Then he went out to the street to wait for either his friend or the police.

He said he had not called police, but was ``pretty certain'' his friend had.

``I was pretty straightforward on the phone,'' he said.

``So I just waited.''

Tunks was arrested about 10pm near the TRC Hotel with the hotel room key in his pocket.

He refused an interview the next day and was interviewed on August 27, while his lawyer Adrian Hall sat in the corner of the room.

Tunks leaned away when showed photos of Miss Kupsch's body.

Prosecutor John Ransom said Tunks's 18-page criminal record contained priors for assault, armed robbery and domestic violence.

Tunks was given a 10-month suspended sentence in June for convictions including an assault against Miss Kupsch on a Mowbray street, when he attempted to force her into a car.

Mr Ransom said Tunks was on a family violence order on the night that he killed Miss Kupsch, and was banned from approaching her.

Mr Hall said Miss Kupsch had chosen to go to the hotel with Tunks.

He said Tunks should not be sentenced as if he intended to kill her.

Miss Kupsch's mother, Donna Kupsch, said she hoped her daughter's case would be a wake-up call for those living with domestic violence, and family members wore white ribbons in court during yesterday's hearing.

Tunks will be sentenced by Chief Justice Ewan Crawford on December 18.