The gunman who shot his estranged wife dead at a Gold Coast McDonald's restaurant has died in hospital of a self-inflicted gunshot wound.

Karina Lock, 49, was shot in the head by her 57-year-old estranged husband Stephen Lock in front of diners at the Helensvale McDonald's yesterday.

She died at the scene.

Lock was taken to hospital with a self-inflicted gunshot wound and died today.

The restaurant has just reopened and the flag outside is flying at half mast.

Local Brittany Wagstaff, who laid flowers at the site today, said the attack had hit close to home.

Stephen Lock, 57, died in hospital earlier today. ( Supplied: Facebook )

"I only live just around the corner so to have this happen so close to home is really scary, I guess," she said.

"Kind of feeling a bit unsafe around here at the moment — I'm not going to lie.

"Laying flowers is like my little tribute to her.

"The recent week has been really hard around here, so it's nice to just show my thoughts to the ladies and men I guess who have dealt with domestic violence.

"It is definitely hard to know all this is happening around us at the moment — it's definitely making us feel unsafe, but I know the police are doing the best they can.

"I know that things are getting changed right now with the whole domestic violence situation, so it's good we're finally taking a stand and we're going to be doing something about it."

Karen Colquhoun-Smith also laid flowers outside the restaurant.

"A woman has just been killed and her children and her family have to live with that," she said.

"These people who kill their partners are cowards."