Detective Sergeant Terrance Fraser was the first to give evidence at Wellington District Court this morning on behalf of police.
Fraser said police had been aware of seven incidents of Fischer harming or attempting suicide between 2000 and 2010.
They included overdosing on drugs and mentioning he had "had enough".
Fraser said that on April 17, 2015, it was reported Fischer had been banging his head on a wall in a bathroom.
His mood appeared to be low and a nurse spent time reassuring and assessing him.
Fischer said "he was tired of it all and wanted it to be over". When his mood improved, he wanted some quiet time to play guitar in his room.
A nurse left him at 5.20pm and said they would come back and check at 6pm.
At that time Fischer was found in his room unresponsive and was transferred to hospital. He died three days later.
His mother, Lyn Copland, took a case against the health board over his death.
In a 2017 Give A Little fundraising page, Copland said she "can't get her boy back, but she's determined to expose the mental health system's flaws".
"Sam Fischer died in the one place he should have been safe - Wellington Hospital's secure mental health unit.
"I want Sam's legacy to be improving the mental health system for others."
The DHB reached a settlement with Copland in April 2018.
In a statement, they said Sam was well liked by staff who knew and cared for him, and they have all felt his loss.
"The key recommendations from the serious adverse event review have been actioned."
A CCDHB staff member gave evidence at the inquest and said the assessment and treatment of Fischer "did not fall below expected standards".
They said the board has accepted all findings and recommendations in previous reports into the death and responded accordingly.
One report said the risk of attempted suicide should've been a more prominent feature in Fischer's management at the time and documentation surrounding risk management should've been better.
The DHB accepted risk documentation wasn't adequate.
The staff member said there had been a significant improvement and immediacy in day by day records since, with a client pathway and shared digital client records shared between the three DHBs in the region.
The inquest is continuing for several days.