The Sacramento Police Department has released a segment of body worn camera which shows officers being attacked by a gunman when they responded to a call from the home where their trainee was shot dead on Wednesday.

Police believe 45-year-old Adel Sambrano Ramos was watching them from security cameras around the property where two assault rifles, one shotgun and one handgun were strategically placed and his front door was barricaded.

Video shows an officer who was nearby Tara O'Sullivan, 26, when she was killed, call: 'Police Department. If you're in here let me know. You're not in trouble, dude.'

But then the father-of-two - and a grandfather with a long history of violence against women - begins incessantly firing in what cops say was an ambush that strung out for four hours.

Police in Sacramento named Adel Sambrano Ramos, 45 (left), as the man who shot and killed rookie officer Tara O'Sullivan, 26 (right) while she was helping a victim of domestic violence

New footage shows male officer call: 'Police Department. If you're in here let me know. You're not in trouble, dude' but the gunman starts firing

The clip shows the officer running away at approximately 6.10pm - the start of the stand-off where Ramos began firing at least 30 separate times. He had multiple cameras in his residence and cops believe they were being watched during the incident.

'It is clear by the suspect's actions that he was intent on murdering additional officers and was taking action to do just that, repeatedly shooting at officers throughout much of this incident,' Police Chief Daniel Hahn told reporters Friday.

On Saturday police shared an aerial shot of the scene over the home from the time of the incident. Three photos feature various weapons they say were used by Sambrano as he attacked officers from behind with a high-powered rifle, including O'Sullivan who was wounded several times but received a 'non-survivable injury'.

Police say O'Sullivan was helping a woman gather her belongings to move out of a home in the North Sacramento neighborhood when she was shot.

'She was helping a woman get away from an environment she didn't want to be in and helping her get her belongings,' Police Chief Hahn said Friday. 'She paid the ultimate sacrifice to do that.'

Sgt. Vance Chandler said an armored vehicle was brought in after the initial shooting, at approximately 6.13pm to rescue the wounded officer, but it took more than 45 minutes to get her to a hospital because the gunman kept firing a rifle.

The standoff in the 200 block of Redwood Avenue at approximately 6.15pm an officer arrived at the nearby police station for the armored vehicle and was at the property by 6.22pm.

New images show how the front door to the house was barricaded during a four-hour stand-off on Wednesday in Sacramento, California

Saturday, police shared an image of the scene of the incident that lasted from all day and night

Two assault rifles were strategically placed around the property on Wednesday, police say

One shotgun and one handgun were also discovered by police after the ambush ended

But as it moved to breach the fence of the backyard, the suspect fired multiple times at the armored vehicle.

Multiple officers left the armored vehicle to rescue O'Sullivan once inside the yard and the gunman continued to fire as they backed out of the property.

However the vehicle transporting O'Sullivan to hospital became disabled so she was carried to a police vehicle where a California Highway Patrol (CHP) Officer rendered aid on her way to hospital.

Crisis negotiators tried to make contact with him at 9.38pm after delivering a cell phone to him by a robot, but the suspect kept shooting with any sign of movement until 10.29pm.

They were finally successful at 10.40pm when he surrendered without injury after two hours of efforts from the crisis team.

'It is clear by the suspect's actions that he was intent on murdering additional officers,' Police Chief Daniel Hahn told reporters Friday

Sacramento police officers respond to the shooting on Redwood Avenue in the Noralto neighborhood Wednesday

A law enforcement officer climbs into a tactical vehicle during the standoff Wednesday

SPD Live: Officer Tara O’Sullivan being escorted to the funeral home Posted by Sacramento Police Department on Friday, 21 June 2019

Online jail records show Ramos was booked into the county's mail jail facility at 5.55am on counts of felony murder and misdemeanor battery.

The 5-foot-9, 185-pound Ramos is being held without bail pending his next court appearance scheduled for June 24.

According to reporting from the Sacramento Bee, Ramos has a criminal record dating back to at least 1995, which includes multiple charges of domestic violence and battery, theft and DUI.

His most recent run-in with the law preceding Wednesday's incident took place last September, when he was arrested for allegedly attacking a young woman at the same home on Redwood Avenue where the police standoff took place overnight.

Slain officer Tara O'Sullivan received a police escort to her funeral home on Friday

Tara O'Sullivan is pictured during her graduation ceremony at College Park High School in Concord, California, in 2011

In that case, Ramos was charged with 'willfully and unlawfully [using] force and violence.' Given that the charge was a misdemeanor, Ramos was released pending a trial and barred from having contact with the victim.

A warrant for his arrest in that case was issued on June 10.

Records indicate that Ramos was accused by his wife of domestic violence in 2003.

In April 2007, Ramos again was accused of the same crime targeting another woman.

On Thursday, the man's estranged wife, Sarah Ramos, told the Sacramento Bee that he was a good man and a good father to their two children. The couple, who had been married for a decade before separating, also have a granddaughter.

Ramos' neighbor told the paper that the murder suspect has always been polite, and enjoyed hunting and fishing.

O'Sullivan had only been a police officer for six months when she was killed, after graduating from the force's police academy in December and joining last January.

KTXL-TV reported that the officer was hit and then pinned down in a yard.

A sheriff's officer in tactical gear is pictured on the scene of the standoff in Sacramento

The gunman surrendered to police early Thursday morning after a tense eight-hour standoff

A law enforcement officer mans a barricade near a home on Redwood Avenue during the standoff overnight

Stephen Nasta, a professor at the John Jay College of Criminal Justice and a former inspector with the New York Police Department, said taking 45 minutes to reach a wounded officer was 'unacceptable.'

'If there's somebody shot, lying on the ground, you have to do everything you can,' Nasta said.

If no such vehicle was available, he said he would expect officers to use a diversionary tactic such as firing at the home, deploying smoke grenades or breaking a door or window in another part of the home to distract the gunman as other officers rescued the downed officer.

Just before 7pm, officer O'Sullivan was brought to UC Davis Medical Center, where she later succumbed to her injuries following surgery.

A memorial fund was set up for the officer.

'We have been overwhelmed with the outpouring of support for Tara's family and our department from our community, our allied law enforcement agencies, communities and agencies from all over this country and even internationally,' Sacramento Police said Friday.

'We would love nothing more than to thank each and every one of you personally but we wouldn't want to leave anyone out. Your support in our time of loss means more to us than we could possible express in mere words.'

She received a police escort to her funeral home on Friday.

O'Sullivan (center) was part of the first class of graduates of Sacramento State's Law Enforcement Candidate Scholars program in 2017