SOUTH PASADENA (CBSLA.com) — A former LAPD homicide detective unveiled new evidence Thursday that he says reveals who killed the Black Dahlia.

Steve Hodel believes the killer was his own father.

Hodel’s father George was booked in 1949 for incest and child molestation. He was also a prime suspect for the 1947 never-solved Black Dahlia murder.

Hodel spoke to a rapt audience at the Pasadena Library Thursday evening.

After his talk, he spoke to CBS2’s Serene Branson.

Authorities long believed someone with medical knowledge committed the gruesome torture and slaying. Elizabeth Short, an aspiring actress, was cut in half with medical precision in January 1947.

Steve Hodel’s father was a doctor.

“What my father did was actually carve, surgically carve into Elizabeth Short’s hip a symbol, a very unique symbol with a criss cross.”

In an interview with the Pasadena Star News last week, the author said he planned to show a link between the crime and the work of an artist who was a friend of his father. The link centers on a little-known Man-Ray painting and distinctive scalpel cuts carved into Short before her death.

“It’s another important piece of the puzzle,” Hodel said.

Short’s body was dumped in Leimert Park. The then 22-year-old woman’s body was drained of blood.

He also says he found receipt for cement sacks, some believed to have been found at the crime scene.

Hodel claims his father once said, “What if I did kill the Black Dahlia, they can’t prove it now.'”

Hodel also says letters written by the killer to the police match his father’s distinct handwriting.

The crime has gripped the nation for decades. For almost as long, the records were sealed.

The case was reopened and is being investigated by a cold case detective.