Double-amputee sprinter Oscar Pistorius, who made history last summer by competing for South Africa at the London Olympics against able-bodied runners, was arrested Thursday in the fatal shooting of his girlfriend at his home in Pretoria.

Pistorius, nicknamed "Blade Runner," is due to appear in

court later today. Local reports have indicated that the 26-year-old Pistorius may have mistaken his model girlfriend for a burglar.

In one of her final Twitter posts, Steenkamp looked forward to spending Valentine's Day with Pistorius, writing, "What do you have up your sleeve for your love tomorrow???"

Sarit Tomlinson, Steenkamp's publicist, joined Fox and Friends by phone just moments ago. But information on the circumstances surrounding the shooting remains thin. She noted that right now "everyone is shocked" by the news.