"I'm not going to elaborate on it but there have been incidents (at Pistorius' home)," Beukes said.
Capacity Relations, a talent management firm, earlier named model Steenkamp as the victim of the shooting. Police spokeswoman Lt. Col. Katlego Mogale told The Associated Press that officers received a call around 3 a.m. after the shooting.
A 9 mm pistol was recovered and a murder case opened against Pistorius.
Mogale said when police arrived they found paramedics trying to revive a 30-year-old woman, who had been shot four times. Mogale, who was speaking to the AP from the scene, said the woman died at the house.
Police have still not released the name of the woman, but the publicist for Steenkamp confirmed in a statement that the model was dead.
"We can confirm that Reeva Steenkamp has passed away," Steenkamp's publicist Sarit Tomlinson said. "We are in communication with people on the scene, please wait for official statements, as there is too much speculation at this moment in time. We will provide further information as soon as we are able to provide accurate information as to what transpired.
"Our thoughts and prayers go to the Steenkamp family, who have asked to have their privacy respected during this difficult time, everyone is simply devastated. She was the kindest, sweetest human being; an angel on earth and will be sorely missed.
Tomlinson said Steenkamp, known simply as Reeva, was one of FHM's (formerly For Him Magazine) 100 Sexiest Women in the World for two years running, appeared in countless international and national advertisements and was one of the celebrity contestants on Tropika Island of Treasure, filmed in Jamaica.
On Twitter, she tweeted messages urging women to stand up against rape alongside her excitement about Valentine's Day. "What do you have up your sleeve for your love tomorrow?" she tweeted. "It should be a day of love for everyone."