A miscarriage sometimes happens because there is a weakness of the cervix, called an incompetent cervix, which cannot hold the pregnancy. A miscarriage from an incompetent cervix usually occurs in the second trimester. There are usually few symptoms before a miscarriage caused by cervical insufficiency.
Police perjury (or testilying in United States police  slang) is the act of a police officer giving false testimony. It is typically used in a criminal trial to make the case against a defendant who the police believe to be guilty when irregularities during the suspect's arrest or search threaten to result in acquittal.
The crime of lying under oath or making a false statement on an affidavit. In order to be considered an act of perjury, the false statement must relate to the matter at hand; it would not be perjury, for example, to falsely state a person's eye color unless it involves the identification of a defendant. Prosecutions for perjury, however, are fairly unusual.