A woman has killed herself days after a man was cleared of raping her, prompting Greater Manchester's police chief and his crime commissioner to call for "root and branch" changes to the way vulnerable witnesses are dealt with in court.

The Independent Police Complaints Commission (IPCC) is investigating after Tracy Shelvey, 41, a mother-of-one, jumped off a multi-storey carpark at Wheatsheaf shopping centre in Rochdale on Monday. She had given evidence against Patrick Hall in two trials – a jury failed to return a verdict on her claims the first time around.

On Friday, at a retrial at Minshull Street crown court in Manchester, he was found not guilty of raping her and two other women. Officers who visited her that night said she was angry and upset at the news and she was offered help from other agencies.

Shelvey's apparent suicide came a year after violinist Frances Andrade took her life during the trial of choirmaster Michael Brewer, who was later convicted of sexually assaulting her when she was a pupil at Chetham's School of Music in Manchester.

Andrade told friends she had not received enough support from Greater Manchester police before and during the trial, and said she felt as though she had been "raped all over again" after undergoing a gruelling cross-examination in court.

Sir Peter Fahy, chief constable of Greater Manchester police – whose officers tried and failed to coax Shelvey down from the carpark before she fell – called for a rethink of the UK's adversarial justice system.

He said the system put too much weight on the victim, adding: "The focus should be more on the ways in which we can control this type of offender."

Fahy said he agreed with Tony Lloyd, police and crime commissioner for Greater Manchester, who on Tuesday said lessons needed to be learned from Shelvey's death.

Lloyd said: "The court process is a brutal one, and the fact that we have had at least two people in Greater Manchester alone who have taken their lives after going through this ordeal is of grave concern.

"Many, many rape victims say that the court process is as traumatic as their original ordeal. This can't go on – a root and branch review of how victims and witnesses are treated is urgently needed. A chain of vulnerability exists from the moment someone reports an incident to police, and it can break at any point.

"We need to ensure that victims and witnesses are surrounded by support from when they report to police, throughout the investigation, the court process and – critically – after trial is over, whether the accused is found guilty or innocent."

Fahy added: "There is a real issue with how we deal with victims of child sexual exploitation, rape, in terms of them having to go into the court system and inevitably there being so much weight put on to the evidence of the victim … If your house is burgled, nobody says it's your fault because the front door is open, [but] if you're a victim of rape or sexual offences there is a massive focus on your credibility, your character, your emotions, what you did on the night, what you were wearing, your other relationships.

It's often in the nature of domestic violence that offenders will pick on people who are particularly vulnerable – and then the vulnerability is exploited by the system."

He said his officers were not trained mental health specialists and could not be there round-the-clock for victims. He said: "The officers can't be there when they're in the dock and giving evidence. There can be a not guilty verdict and the trouble is that officers aren't really there at those dark moments."

Shelvey's family described her as "a kind and caring person" who was close to her "loving" family. They said: "She had a warm heart and was a loyal friend and will be deeply missed by all. We are so proud of Tracy for standing up in court on the two trials. She was a strong person with a lot of pride."

• This article was amended on 5 February 2014. The original said that: "Officers who visited her that night said she was angry and upset at the news and she was offered help from other agencies including Victim Support". While Victim Support had offered support previously they had not done so on that occasion.