She was found safe in upstate New York after an exhaustive search. A suspect was taken into custody, police said.
MOREAU, New York (WABC) -- The 9-year-old girl who went missing last weekend while on a bike ride at an upstate New York park has been found and a suspect taken into custody, police announced Monday evening.
New York State Police said they identified an individual as being in the area of the Moreau Lake State Park around the time she went missing.
A break in the case came around 4:20 a.m. Monday morning, when a car pulled up to the home of the girl's family and placed a ransom note in the mailbox.
State Police immediately began to look for a match with a fingerprint found on the letter. A match was found around 2:30 p.m. linking the fingerprint to a 1999 DWI arrest in Saratoga.
It led police to a house where the suspect's mother was found. They found the suspect, 47-year-old Craig Nelson Ross Jr. in a camper behind the home.
He was taken into custody. New York Gov. Kathy Hochul said charges have yet to be filed against him, but they are expected.
Sena was immediately found in a cupboard, both safe and in "good health." She was taken to a local hospital and reunited with family.
"This investigation is a culmination of multiple agencies working together for the common goal of bringing this child home to her loving family," New York State Police said in a statement. "We cannot emphasize enough how appreciative we are for the support we received from (the girl's) community, friends and family."
"We are overjoyed at the news that (she) has been located safely this evening after an intense days-long search," New York Gov. Kathy Hochul said in a statement. "Our hearts are with her family as they welcome her home. Thank you to the New York State Police, New York Park Police and all who worked so tirelessly to find (her). It is because of their efforts that (she) will be able to return home safe to her family."
The events unfolded when law enforcement officials first issued the Amber Alert Sunday morning after an exhaustive search because "it was quite possible that an abduction had taken place," state police Lt. Colonel Richard Mazzone said."
The alert described her as a white girl with blonde hair and green eyes, about 4 feet 6 inches tall. She is a resident of Greenfield, New York.
Police say that the circumstances of her disappearance lead them to believe she was in imminent danger.
Before she was located on Monday, she was last seen riding a bike with friends on Saturday evening in Moreau Lake State Park, about 35 miles north of Albany.
She had been riding her bike around a loop in the park with other children when she decided to ride around one more time by herself. Her parents became alarmed when the fourth-grader failed to come back after 15 minutes, Gov. Kathy Hochul said at a briefing Sunday.
The girl's mother called 911 to report her daughter missing after her bicycle was found about 6:45 p.m. Saturday.
About 400 people took part in the search Monday, up from more than 100 the day before, state police said. The searchers included state and local police, forest rangers, local volunteer firefighters, and some private search and rescue groups, officials said. Authorities also requested help from the FBI.
The search expanded over 46 linear miles (74 linear kilometers) by Monday, state police said.
Troopers set up several checkpoints on the rural roads around the park. They stopped drivers and asked if they knew the family, had seen the girl's photo or had any other information. They also had some drivers open their trunks.
Federal authorities also issued a temporary flight restriction over the park for the safety of law enforcement air operations.
"We are leaving no stone, no branch, no table, no cabin unturned, untouched, unexamined in our search to find (her)," said Hochul, who described her as a "joyful" girl who was recently elected a class officer for student council.
The girl's family pleaded with the public for help, including providing any tips to the state police.
"We just want her returned safely like any parent would," the family said in a statement. "No tip is too small, please call if you know anything at all."
ABC News and the Associated Press contributed to this report.