Compton shooting: Key witness sought in ambush that left 2 sheriff's deputies wounded

COMPTON, Calif. (KABC) -- Los Angeles County Sheriff's Department investigators want to speak to a key witness, seen on surveillance video, in connection with the ambush shooting of two deputies in Compton.

In the footage, recorded Saturday night, the witness who is now being sought can be seen walking nearby on the sidewalk as the gunman runs away from the deputies' parked SUV.

The male deputy who was shot has since been released from the hospital.

The female deputy remains in the intensive care unit but is expected to recover. Neither deputy has been publicly identified.

RELATED: Video shows wounded deputy struggle to aid partner after Compton shooting

As a manhunt continues for the gunman who ambushed two Los Angeles County sheriff's deputies in Compton, new surveillance footage shows how one deputy struggled to help her partner even as she was bleeding from her own wounds.

The reward for information leading to an arrest and conviction has now increased to a combined total $640,000

The Los Angeles County Board of Supervisors had initially authorized a $100,000 reward.

By Thursday, the reward was around $675,000, according to the Sheriff's Department. The offer has grown due to various contributions, including $75,000 from the Association for Los Angeles Deputy Sheriffs and $25,000 from the Los Angeles County Metropolitan Transportation Authority. Two private donors also added $75,000

WATCH: Protesters show up to hospital after Compton deputy shooting

A small crowd of demonstrators gathered outside a Lywood hospital Saturday night where two L.A. County Sheriff's deputies are being treated. Shortly after, a local radio reporter was arrested during a scuffle with deputies.