It depends on where he says it. For example, if he says it on the side of the road when he is hoping to get you to confess then it's not... if he says it in a sworn statement it might be perjury, if he says it while testifying under oath it might be aggravated perjury. Turn to chapter 37 in the Texas Penal Code:
Sec. 37.02. PERJURY.
(a) A person commits an offense if, with intent to deceive and with knowledge of the statement's meaning:
(1) he makes a false statement under oath or swears to the truth of a false statement previously made and the statement is required or authorized by law to be made under oath; or
(2) he makes a false unsworn declaration under Chapter 132, Civil Practice and Remedies Code.
(b) An offense under this section is a Class A misdemeanor.
Sec. 37.03. AGGRAVATED PERJURY.
(a) A person commits an offense if he commits perjury as defined in Section 37.02, and the false statement:
(1) is made during or in connection with an official proceeding; and
(2) is material.
(b) An offense under this section is a felony of the third degree.
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Note: No matter how convincing the evidence, there is almost zero chance that they would ever charge a cop with perjury because that would undermine the prosecution of all the cases he has worked on.
