(WASHINGTON) -- A 20-year-old American named Kevin Dahlgren accused in the grisly murders of a family of four in the Czech Republic has been arrested in the United States.
Czech police had targeted Dahlgren and circulated a picture from his Facebook account to police stations, border posts, immigration counters and media outlets across the country. Authorities in neighboring countries had reportedly been alerted to detain Dahlgren, whose Facebook description says he is from Palo Alto, Calif. Police spokeswoman Petra Vedrova told ABC News the suspect may be armed and dangerous.
"Police took measures to stop him from leaving the country, and we're in contact with all neighboring states," she said.
Neighbors said Dahlgren had been visiting his aunt and uncle, Veronika and Martin Harok, and their two sons, 22-year-old Filip and 18-year-old David. They were all found dead by firefighters who responded to what they believe was an attempt by the alleged killer to cover up his crimes.
"We were originally called to intervene against a fire. On the spot the suspicions arose that a violent crime had been committed. We immediately called the police," firefighters' spokesman Jaroslav Mikoska told ABC News.
Veronika Harok was a Czech language teacher at the local elementary school. Martin Harok and his son Filip were musicians who played several nights a week with a local ukulele orchestra, while the youngest victim, David Harok, was described as very involved with sports.
Bozena Zikuskova, a local restaurant owner, told ABC News that Dahlgren would come every other day and always order the same meal. She noted that Dahlgren's Czech was not even good enough to order a meal.
Karel Herman, the front man of Ukulele Orchestra Jako Brno band in which Martin and Flilp Harok played, said "Dahlgren was just visiting his cousins. He arrived in early May and was a completely normal guy."
Neighbors said the crime had shocked the community.
"It's not something you expect from the neighborhood," said , Jan Kral, 56, who said he had lived in the area for 30 years. His wife, Paulina, agreed. "It's frightening," she said. "Very frightening."
In Washington, State Department spokesman Patrick Ventrell offered no more information than the Czech authorities, saying, "We are aware of this tragic incident and are working with Czech authorities. For any information about the investigation, we refer you to the Czech National Police."
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