A police chief has described in detail the 'shocking' footage of the moment a Google executive suffered a lethal heroin overdose on his yacht with a high-end escort.

Father-of-five Forrest Hayes, 51, had just taken up a job at the top secret Google X office - where the firm makes unimaginable inventions a reality - when he died in Santa Cruz, California, in November 2013.

The only other person aboard the yacht was Alix Tichelman, 27, who will be tried for manslaughter, drug charges and prostitution on February 23. She is pleading not guilty.

And the entire case hangs on a video of the entire night.

It took three months and a court order to obtain the footage - which changed everything.

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Intense detail: Police describe a video that allegedly shows high-end escort Alex Tichelman, 27, (left) giving Forrest Hayes, 51, (right) a lethal dose of heroin aboard his yacht, before 'cleaning up and walking out'

Pleading not guilty: Tichelman will appear in court on February 23 where she will deny manslaughter charges

'Initially, we were told that the video wasn't available from that particular camera - that actually showed the cabin of the boat. There was indeed video that was uploaded to a cloud server. And the video from that camera was indeed available,' Santa Cruz Deputy Police Chief Steve Clark tells 48 Hours in a new documentary about the case.

'That was one of those moments where you feel like, you know, it was 4th and 1. And you got a first down.'

Actually, it took three months and a court order for detectives to get their hands on that video. When they did, it was explosive.

'That video was shocking to me,' said Clark, according to CBS.

'Well, the video's everything. The video is the case.'

Describing the footage, which has not been seen by the public, Clark tells reporter Maureen Maher: 'They greet each other - a quick hug - just a quick embrace. You can see that they're engaged in conversation. But there's no audio,' Clark said.

'Then, eventually, she gets to the point where she starts to prepare drugs... for injection.

'We see her very clearly. She brought all of the equipment with her. She brought the drugs with her.

'We see her prepare the syringe. We see her - it looks like she's injecting herself, but her back's to the camera.

'He watches this happen. And then she eventually injects him.'

Clark adds: 'I get the impression... he's nervous. He's uncertain. But he's going along with it.

'Almost immediately, he starts to go into distress. At some point, she comes to him. It looks like she tries to revive him a bit... by patting him on the face and talking to him, holding his head as he slumped forward on the chair.

'And you or I, if we found ourselves in that situation, would've been on the phone to 911, saying: "Oh, my gosh. Something terrible's happened. We need help." And she does none of that.'

In a move that will likely prove crucial to the case, Clark says, Tichelman is seen cleaning up the drugs, wiping fingerprints from the scene, then stepping over Hayes's lifeless body to leave.

'She is literally walking around the cabin of the boat... stepping over him, grabbing her glass of wine, carrying it around the boat cabin with her,' he says.

Accusations: Police claim a video shows Tichelman watching Hayes die before stepping over him

On board: Tichelman's lawyers want police to release a surveillance video taken from the Santa Cruz yacht where Hayes was found which they claim proves it was an accidental, consensual overdose of heroin

For seven minutes, he tells Maher, Hayes is left alone.

'And that's seven minutes that emergency medical personnel could've been there could have done something and could have reacted to this situation to save Mr. Hayes' life. But instead, she does nothing, nothing to call for help or to fix this. You know, and that's the crux of the case,' Clark said.

Clark's words come as Tichelman prepares for her trial, beginning in February.

Tichelman has pleaded not guilty to charges of manslaughter, prostitution and transportation and sales of narcotics. She remains jailed in lieu of $1.5 million bond.

'We've always been curious in regard to Mr. Hayes' receptiveness, if not welcoming purchase, of drugs,' public defender Jerry Christensen told the judge on Friday. 'It would make a great deal of difference in regard to the drug crimes.'

At her latest court appearance, in December, Tichelman rolled her eyes at camera crews and reporters as she entered the courtroom dressed in orange jail garb.

Tichelman, 27, was arrested eight months later after police discovered the harbor's surveillance video.

The squad lured her to her arrest by using a fake social media profile, posing as a potential client.

'My client Alix didn't do anything to Mr Hayes that he didn't want to happen to him,' defense attorney Larry Biggam said at a procedural hearing today, according to NBC.

'She did what she was asked. Consensual adults involved in mutual drug usage. It went wrong but it wasn't intended.'

Biggam also called on police to release the full surveillance video taken from the boat, which prosecutors are using as evidence for a number of allegations.

Her defense team has only seen 20 minutes of the footage described in court but Biggam insists it shows the overdose was 'accidental'.

She now faces eight charges which all carry 15-year jail terms, including manslaughter, prostitution, destroying evidence and several related to administering and possessing heroin.

Tichelman, who met her clients through a website called Seeking Arrangement, had exchanged texts and emails with Hayes and met with him a few times before the deadly November 26 encounter.

Charges: Tichelman is facing up to 15 years for eight charges including manslaughter and prostitution

Lured: She was arrested after law enforcement officers posed as a client and lured her to a Santa Cruz hotel

That day, they met on Hayes' 50-foot yacht, Escape, at the Santa Cruz Small Craft Harbor and Tichelman brought heroin before injecting him with the drug, police said.

Authorities launched a nine-month investigation into the incident before eventually uncovering Tichelman's correspondence with the victim.

They then tracked her down to her home in Folsom, where she lives with her parents, but lured her back to Santa Cruz County by posing as a client who said he wanted to pay her $1,000 for sex. She agreed to meet at a luxury hotel on Fourth of July and was arrested.

Hayes, who was originally from Dearborn, Michigan was married for 17 years to wife Denise and together they had five children, according to his obituary.

He worked in the auto industry before senior roles at Apple and Google.

'Forrest will be remembered above all as a loving husband and father. More than anything else he enjoyed spending time with his family at home and on his boat,' according to a January obituary.

'His brilliant mind, contagious smile and warm embrace will be missed and cherished in memories by his friends and family.'

Tichelman's Facebook profile shows she went to high school in Atlanta before majoring in journalism at Georgia State University and attending beauty school. She lists her occupation as a makeup artist.

She called herself a 'model' in jail records.

On social media, she poses in lingerie and pouts with red lips for the camera.

In an interview with fiXE fETISH magazine, she said she loved modeling because she got to play a character.

'I have always been attracted to the darker side,' she said. 'My parents said by the time I was three I was an 'intense child' and already liked horror movies.'

She added that she loved fetishism and would often wear a leash when she went out with her boyfriend.

She also posted pictures under another Facebook profile, AK Kennedy, and talks about heroin and her love of the serial killer TV show, 'Dexter'.