Pressed for a serious answer, Davis said the request for counsel should protect the suspect from further questioning indefinitely -- prompting justices to ask if that would give someone a permanent shield from talking to police.
Gansler suggested a seven-day period.
"The state opens the bidding with seven days," Justice Anthony M. Kennedy joked.
Justices also dissected whether Shatzer was "in custody" the entire time between the police interviews.
Gansler argued that Shatzer was in custody in prison, but not in police custody.
The 1981 Edwards v. Arizona case says someone can stop answering police questions if he or she doesn't have a lawyer, a protection against badgering.
Justice Ruth Bader Ginsburg said a prisoner -- unlike someone who is free -- can't contact an attorney.
Justice John Paul Stevens asked several questions about what specific instructions Shatzer was given about exercising his right to counsel.
Gansler said Shatzer could have asked for an attorney in the two years and seven months, but didn't. When a second investigator questioned him, Shatzer had "a mental reset" and agreed to talk, Gansler said.
Outside the court, after the hearing, Gansler said it was "exhilarating" to argue a case for the first time before the U.S. Supreme Court.
Shatzer, 51, was serving time at Maryland Correctional Institution-Hagerstown in 2003 for a conviction of sexually abusing a juvenile.
A court brief says Detective Shane Blankenship, acting on a tip, asked Shatzer at MCI-H to talk about the possible abuse of another child. Shatzer said he didn't want to talk without a lawyer present, so Blankenship ended the interview.
In 2006, acting on more specific information, another Hagerstown Police detective, Paul Steven Hoover, asked Shatzer to talk.
Shatzer, at Roxbury Correctional Institution at the time, "expressed surprise," but didn't ask for an attorney and talked to Hoover for a half-hour, the brief says.
Shatzer was found guilty of sexual child abuse in the later case and was sentenced to 15 years in prison, with 10 years suspended.
Last year, the Maryland Court of Appeals overturned the circuit court's decision to allow Shatzer's statement, saying "the passage of time alone is insufficient to expire the protections" of not talking without an attorney present.
Mark Vernarelli, a spokesman for the Maryland Department of Public Safety and Correctional Services, said Shatzer is serving time for second-degree sex offense and child abuse and is expected to be incarcerated until 2017.
o The case is Maryland v. Shatzer, 08-680.
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