In the days following the capture of millionaire fugitive Peter Chadwick, who spent more than four years on the run after he was charged with killing his wife, authorities are learning more about the California native's life on the lam – including the fact that he allegedly pretended to be a secret agent to avoid capture.

Chadwick, who was captured in Mexico on Sunday, is accused of strangling his wife to death in their Newport Beach mansion in 2012. A judge denied his bail this week.

But before he was discovered, Chadwick tried to blend in with the locals at San Andrés Cholulua, according to U.S. Marshal Craig McCluskey.

"The make-up of the town was mostly Caucasians…but also an Asian community as well," McCluskey said.

It was a world away from the mansion in posh Newport, California, that he once shared with the woman police say he murdered: his wife, Q.C. Chadwick. He later fled, leaving behind his three sons. But while his hideout was a modest apartment next to a country club, McCluskey said that he didn't entirely leave the high life behind.

"[The club] had tennis courts… and of course, you know, Peter preferred playing tennis," McCluskey said.

"So he continued to play tennis?" asked "48 Hours" correspondent Tracy Smith.

"Yes," McCluskey responded.

Mexican federal police also recovered several fake IDs, one of which caught the attention of U.S. marshals.

"It was a copy of some fictional security force. And he was representing himself as some type of analyst with top secret access…" McCluskey said. "Maybe to get some unassuming local police officers off his back."

But after more than four years, Chadwick's secret was exposed -- and now, he sits in a Southern California jail facing a charge of murder that could result in a life sentence behind bars.

Smith and "48 Hours" will have the latest in the case in "Peter Chadwick: Caught" airing Saturday night at 10/9 Central on CBS.