text: John Truong thought he was helping his sister have a nice night out with her boyfriend. Instead, he ended up an unknowing accomplice to a bizarre abduction. Police arrested Truong's sister Alyssa Chang this week after she allegedly helped kidnap 2-year-old Ronnie Tran and his mother, with the child's grandmother, 65-year-old Vien Nguyen. Authorities say Chang and Nguyen incapacitated the child's mother at her home in Des Moines, Washington, bound her with plastic ties and then took the two to another home in Fife. Chang and the grandmother then took off the the toddler, leaving the mother locked in a cupboard. An Amber Alert was issued for the boy Tuesday night, after the mother managed to escape and find help. Scroll down for video . Babysitting: John Truong agreed to babysit 2-year-old Ronnie Tran (pictured) on Tuesday. He says his sister dropped off the boy, saying the toddler was her boyfriend's son and they wanted to go on a date night . That same night, Truong says his sister asked him to babysit the toddler he had never met before, saying it was her boyfriend's son and they wanted to go out on a date night. She promised to pick up the boy in the morning, but she never returned and eventually stopped answering her brother's messages. It wasn't until the next day that Truong realized he was harboring an abducted child when he read an Amber Alert on online. 'I'm eating my breakfast, I'm checking my Facebook, all of a sudden I see this Amber Alert for this child,' Truong recounted to KOMO. 'And it looks like this child in my bed, and I'm like, "Oh my God! What's going on?"' Truong then called police to report that he was watching the boy, who they found safe, sound an unhurt at his home. Safe and sound: Truong was reading Facebook in the morning when he realized that Ronnie had been abducted from his mother. He then called police, and they picked up the boy (above). Truong's sister Alyssa Chang has since been arrested in connection to the bizarre kidnapping . He says the boy appeared fine the night before, enjoying a quiet night in watching movies and eating popcorn. 'He was a great kid. He didn't cry much or anything. He enjoyed my dog's company and my children's company,' Tuong said. Truong says he was completely taken aback by his sister's arrest in the bizarre kidnapping. 'I feel like she was just helping her boyfriend out and just got into this horrible situation,' he said. 'We're family people, this is definitely not like this. Honestly I'm at a loss for words right now. It's just crazy.' In the aftermath of the incident, Chang was arrested on charges of kidnapping, assault and unlawful imprisonment and is being held on $250,000 bail. Nguyen later turned herself into police and was questioned for several hours. Detectives have yet to reveal a motive for the crime. 'Our detectives are currently investigating this case,' said Sgt Mike Graddon of the Des Moines Police told King 5. 'It's very, very complex, and that is all the information we have at this point, but Ronnie has been found.'
target: John Truong of Renton, Washington says sister dropped off 2-year-old boy Ronnie Tran at his house Tuesday .
  Sister Alyssa Chang told him the boy was her boyfriend's son and they wanted to have a date night .
  While scanning Facebook the next morning, Truong read an Amber Alert issued for the boy and then called police .
  Truong's sister was arrested for kidnapping Tran and his mother, with the help of the toddler's grandmother, 65-year-old Vien Nguyen .
  Nguyen later turned herself into police for questioning .
  The motive for the abduction has not yet been released .