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.
Perjury is the act of deliberately lying under oath. A defendant in a murder trial commits perjury when he swears he never met the murder victim before, even though he had a two-year relationship with her. Although the word perjury contains jury, members of the jury aren't likely to commit perjury, because they're not under oath and haven't sworn to be truthful. A witness in a trial can commit perjury by willfully lying about facts related to the case. Perjury isn't just a little white lie.