Los Angeles police were involved in a fatal shooting Monday night after responding to a call of a man with a mental illness who was acting violently, police said.

The shooting occurred about 8:15 p.m. in the 900 block of East 107th Street in South L.A. The victim was 40 years old.

After arriving at the scene, patrol officers requested additional units, police said.

"The situation started to escalate, and they requested backup," said Officer Karen Rayner, a Los Angeles Police Department spokeswoman.

Investigators were at the scene gathering evidence. No other details were available.