Why do the police hold back information?

[Robittybob1]

Let's debate this aspect of the McCann case.  TBH we would have no idea what information the PJ have held back until it is released at a later time.

But let's look at other cases than the McCann case and see how this is dealt with.

"The Secrets Police Keep
How cops decide which details of a crime to make public."
http://www.slate.com/articles/news_and_politics/explainer/2006/08/the_secrets_police_keep.html

[Robittybob1]

That article is written with the help of a police officer.  It sounds correct to me so I'll copy part of it and take it in.

"According to some news reports, the man arrested for killing JonBenet Ramsey knew details of the case that had not been publicly released. In high-profile cases, police often keep some details about the crime scene secret as they pursue their investigation. How do the police decide which facts to withhold from the press?

They generally keep quiet about a few details that only the killer could know—anything from an object left at the scene to the way a garrote was tied around a victim's neck. The chief detective on a case usually decides what evidence to make public and what to withhold, although his choices are sometimes influenced (or overruled) by the police chief. In a high-profile case, the police department will generally hold a press conference immediately after discovering a crime but release few details about the case. Later, once those assigned to the case have had a chance to sift through the evidence, police will decide which details to make public.

Police withhold evidence to help determine whether suspects they catch are guilty. If a suspect possesses nonpublic information about a crime, police reason, it is likely that he either committed it or knows who did. And a suspect's knowledge of nonpublic information can be used against him in court. Of course, it's tricky to get a suspect to reveal such information. During interrogations, police officers refrain from discussing nonpublic details of a crime in the hopes that a suspect will slip up and reveal that he knows some of them.

Withholding evidence also helps police rule out the possibility that a suspect might be confessing to a crime he didn't commit. False confessors often piece together information about a crime by obsessively tracking news stories and assembling as many details as they can. When questioned by police, they can sometimes offer convincing explanations of how they committed the crime. Police officers are trained to quickly determine whether such suspects know about the evidence they've withheld.

There's no surefire way to ensure that details about a case don't leak out during an investigation, but police generally try to limit the number of people working on a case in order to minimize the risk of leaks.

Explainer thanks former police detective Lee Lofland, author of The Book of Police Procedures and Investigations.

[Robittybob1]

In the Portuguese system of archiving a case I would imagine that information held back is not released along with the file just in case the investigation is reopened.

In that case it would be not true that all the known information appears in the public McCann PJ files.

[Robittybob1]

"Disclosure Failures in Criminal Trials"  https://www.mowbraywoodwards.co.uk/mowbray-life/the-source/insight/disclosure-failures-in-criminal-trials

Is really a separate but important issue and is not what I mean by the police holding back information.

"More than 900 criminal cases were dropped in England and Wales last year due to a failure by police or prosecutors to disclose evidence, it has been reported."

The reasons why the police break the law regarding this would be interesting to know.  Are they so unsure of their case?
"Because who decides who’s guilty?  The job of the police is to investigate whether or by whom an offence has been committed.  They have a legal duty to investigate all reasonable lines of enquiry, whether they point towards the guilt or innocence of a particular suspect.  It sounds simple, but if you are a suspect in a criminal case you need to understand that this isn’t how it works.  This isn't a story of a few rogue cops gone bad, or a crumbling, underfunded criminal justice system overwhelmed by national austerity (though both get blamed daily in courts and the press to cover a wider, more difficult truth).  This is a story of a state funded system designed with political ends in mind to convict those accused of crime, because once a person is charged they must be guilty, if only the Crown can prove it.  Inconvenient evidence that would undermine a prosecution or assist a suspect doesn't achieve either of those aims, so it doesn't have any real importance.  As soon as the police think it is their job to catch the criminals, the system goes wrong, because it is they, not a court or a jury or anyone independent, who is deciding on who is a criminal and then setting about proving it.  As soon as a police officer goes about the job of investigating all lines of enquiry, and simply properly presents that evidence, the system will work so much better."

Gosh what did that say - the PJ should have read it before investigating the McCann case!

"They [the police] have a legal duty to investigate all reasonable lines of enquiry, whether they point towards the guilt or innocence of a particular suspect.

[Miss Taken Identity]

In the Portuguese system of archiving a case I would imagine that information held back is not released along with the file just in case the investigation is reopened.

In that case it would be not true that all the known information appears in the public McCann PJ files.

I can offer a possible explanation. witness protection!  If example a paedophile gang had come across MBM- this is a 'no snitch global community' and one person did come forward with information to have suspects charged they are putting their lives in danger- also local police 'spies' will not be compromised. Local mafia boss may have heard through the grapevine of some interesting information- they would not be trawled out in public either.
1. someone knows who is responsible and is being protected by  xyz community
2. no one is the community knows anything worth while.

[Miss Taken Identity]

"Disclosure Failures in Criminal Trials"  https://www.mowbraywoodwards.co.uk/mowbray-life/the-source/insight/disclosure-failures-in-criminal-trials

Is really a separate but important issue and is not what I mean by the police holding back information.

"More than 900 criminal cases were dropped in England and Wales last year due to a failure by police or prosecutors to disclose evidence, it has been reported."

The reasons why the police break the law regarding this would be interesting to know.  Are they so unsure of their case?
"Because who decides who’s guilty?  The job of the police is to investigate whether or by whom an offence has been committed.  They have a legal duty to investigate all reasonable lines of enquiry, whether they point towards the guilt or innocence of a particular suspect.  It sounds simple, but if you are a suspect in a criminal case you need to understand that this isn’t how it works.  This isn't a story of a few rogue cops gone bad, or a crumbling, underfunded criminal justice system overwhelmed by national austerity (though both get blamed daily in courts and the press to cover a wider, more difficult truth).  This is a story of a state funded system designed with political ends in mind to convict those accused of crime, because once a person is charged they must be guilty, if only the Crown can prove it.  Inconvenient evidence that would undermine a prosecution or assist a suspect doesn't achieve either of those aims, so it doesn't have any real importance.  As soon as the police think it is their job to catch the criminals, the system goes wrong, because it is they, not a court or a jury or anyone independent, who is deciding on who is a criminal and then setting about proving it.  As soon as a police officer goes about the job of investigating all lines of enquiry, and simply properly presents that evidence, the system will work so much better."

Gosh what did that say - the PJ should have read it before investigating the McCann case!

"They [the police] have a legal duty to investigate all reasonable lines of enquiry, whether they point towards the guilt or innocence of a particular suspect.

There are very serious implication to this revelation.Some  men were being persecuted by the establishment, initiated by angry women who sought to accuse them of rape. Apparently some over zealous prosecutors were determined to meet targets? as it was claimed very few rape cases get to court.
The other situations could be blackmail? or  pressure to drop certain cases as not enough evidence will secure a prosecution or the witness retracts. I am sure there are more reasons.

Re McCanns:"They [the police] have a legal duty to investigate all reasonable lines of enquiry, whether they point towards the guilt or innocence of a particular suspect."

We have to define what is reasonable in this particular case. a global witch hunt which is what the McCANNS WANTED.

[Robittybob1]

I can offer a possible explanation. witness protection!  If example a paedophile gang had come across MBM- this is a 'no snitch global community' and one person did come forward with information to have suspects charged they are putting their lives in danger- also local police 'spies' will not be compromised. Local mafia boss may have heard through the grapevine of some interesting information- they would not be trawled out in public either.
1. someone knows who is responsible and is being protected by  xyz community
2. no one is the community knows anything worth while.

Very pertinent points. 

[Robittybob1]

I'm not sure what to say.  But I'm sure glad I'm not a target of an investigation ATM.

[G-Unit]

In Portugal a police investigation is closely related to the courts and their equivalent of the CPS. They are involved from the beginning of the investigation until it's conclusion;

From the Lagos Court

Make a copy of the present files, with a copy of everything that has been processed, as quickly as possible and deliver it to the hand of the Public Prosecutor.

7/5/2007 (17 hours)
http://www.mccannpjfiles.co.uk/PJ/interpreters.htm

The public prosecutor receives copies of the evidence as it's collected. He sees all the evidence so it would be difficult for the police in Portugal to keep evidence out of the official case files. If it's not in those files then by definition it's not evidence.

[Robittybob1]

In Portugal a police investigation is closely related to the courts and their equivalent of the CPS. They are involved from the beginning of the investigation until it's conclusion;

From the Lagos Court

Make a copy of the present files, with a copy of everything that has been processed, as quickly as possible and deliver it to the hand of the Public Prosecutor.

7/5/2007 (17 hours)
http://www.mccannpjfiles.co.uk/PJ/interpreters.htm

The public prosecutor receives copies of the evidence as it's collected. He sees all the evidence so it would be difficult for the police in Portugal to keep evidence out of the official case files. If it's not in those files then by definition it's not evidence.

I take it this part is your own conclusion:
"The public prosecutor receives copies of the evidence as it's collected. He sees all the evidence so it would be difficult for the police in Portugal to keep evidence out of the official case files. If it's not in those files then by definition it's not evidence."

IMO you have insufficient grounds to make such a conclusion.

[G-Unit]

I take it this part is your own conclusion:
"The public prosecutor receives copies of the evidence as it's collected. He sees all the evidence so it would be difficult for the police in Portugal to keep evidence out of the official case files. If it's not in those files then by definition it's not evidence."

IMO you have insufficient grounds to make such a conclusion.

Really? Do you think the prosecutor was only given copies of the evidence up to 7th May 2007?

[Robittybob1]

Really? Do you think the prosecutor was only given copies of the evidence up to 7th May 2007?

I didn't say that or think that.

[G-Unit]

I didn't say that or think that.

What are you saying then?

[Robittybob1]

What are you saying then?

I'm saying your conclusion seems to be more extensive than the evidence you have for your conclusion.  Have you jumped to a conclusion?  I'd like to see a written document examining the actual procedure.

[G-Unit]

I'm saying your conclusion seems to be more extensive than the evidence you have for your conclusion.  Have you jumped to a conclusion?  I'd like to see a written document examining the actual procedure.

In my opinion the evidence is held by both the police and the prosecutor because the prosecutor directs the investigation. This is different from the UK, for example, where the police organise the investigation themselves.