lawyer up, v. — Green’s Dictionary of Slang

lawyer up v.

[‘In the United States, a person subjected to custodial interrogation by the police is entitled to be furnished with counsel, irresepective of ability to pay, before such questioning proceeds, and must be read the so-called Miranda warnings, advising him of this right. Under this regime, the suspect who ‘lawyers up’ most often doesn’t do so on advice of counsel, but in order to exercise his right to be counseled before interrogation proceeds’ former US prosecutor J. Gibbons (personal comm.)]

(US) of an individual subject to police interrogation, to demand mandatory access to a lawyer (who will probably advise them to refuse to answer any — further — questions).

2006		P. Brauner Slipping into Darkness 9: The boy sat in the cinder-block room. [...] ‘He lawyer up, yet?’ Francis watched the boy through the one-way glass.
2017		D. Winslow The Force [ebook] God’d probably shut his mouth, lawyer up, let his own kid take the jolt.
2018		G. Disher Kill Shot [ebook] He lawyered up and employed delaying and withholding tactics.
2021		C. Hammer Opal Country 291: ‘They wanted to give him the once-over before [...] he could think his story through and lawyer up’.