BOSTON -- Police say a tip from the public and a ruse by detectives led to the Baltimore arrest Saturday of Clark Rockefeller, 48, and his daughter Reigh, 7, both missing after an alleged abduction in Boston's Back Bay neighborhood that sparked an international manhunt for the pair.

WATCH: Fugitive Father Nabbed In Baltimore

The girl was found unharmed and was "ecstatic" to see the police when they arrived.

"Her first words were that she was very happy to see nice people. She was very pleased with that. She was ecstatic about that," Noreen Gleason, FBI's assistant special agent in charge of the Boston division said.

Detectives said Rockefeller was staying at an apartment in the Mount Vernon section of Baltimore near the Anchorage Marina, where he was docking his 26-foot catamaran.

They said they lured Rockefeller out of the apartment by telling him his boat was taking on water, then arrested him. He was said to be "very cooperative," on arrest.

"When Clark left the apartment he was immediately placed under arrest by FBI agents. Simultaneously, agents made their way to the apartment to find Reigh. At approximately 3:29 p.m., Reigh was located alone in the apartment where she was reportedly excited to see the law enforcement officials. Her appearance has not been altered and Reigh appears to be unharmed," Boston Police Commissioner Ed Davis said.

Boston Police Deputy Superintendent Tom Lee said the child's mother collapsed in his arms upon hearing the news her daughter had been found safe.

"Reigh's mother, Sandra Boss, was overjoyed by this news. She is being reunited with her daughter and she wishes to express her deepest gratitude to all those involved in bringing Reigh home," Davis said.

He said a "concerned citizen" tipped off authorities to Clark's location but the tipster does not wish to be identified. He said more than 200 tips were received from people across the country during the investigation.

Rockefeller was being held in FBI custody in Baltimore, facing charges that include felony custodial kidnapping, assault and battery with a dangerous weapon and and assault and battery.

He will be arraigned Monday to begin the extradition process.

"Investigators continue their efforts to try to determine Clark Rockefeller's true identity," Davis said.

After the alleged abduction, police said they were unable to come up with a Social Security number for Rockefeller or a previous work history for him.

Rockefeller and Boss were divorced last year after a 13-year marriage in which they lived in Boston's posh Back Bay neighborhood and kept a vacation mansion in New Hampshire.

Boss, a partner in a London management consulting firm, brought Reigh back to Boston July 27 for a supervised visit with Rockefeller when he allegedly grabbed the child and fled in a waiting SUV.

He then reportedly had a friend drive the pair to New York City, where he said he was going to take the girl on a cruise, and the two vanished, sparking an international search that involved Boston police, the U.S. Coast Guard and the FBI.

The girl's mother issued a plea later in the week imploring Rockefeller to return the child to her care.

By all accounts, Rockefeller had raised the child since she was an infant while the mother worked. He ceded custody of her to Boss earlier this year, however, rather than reveal his true identity, according to a Boston Herald report.

Boss paid him nearly $1 million as part of the divorce proceedings, the Herald reported.

Rockefeller has used at least four known aliases, police said.

A spokesman for the famous Rockefeller family, descended from Standard Oil billionaire John D. Rockefeller Sr., said he was not part of the wealthy clan.