A convicted felon wanted in the murder of his pregnant girlfriend and her unborn child was arrested Sunday night, less than two weeks after being added to the FBI’s 10 Most Wanted Fugitives list.

Philip Patrick Policarpio, 39, was arrested by agents with the U.S. Customs Border Protection as he was crossing into the United States from Tijuana, the FBI said in an email statement to Fox News.

Policarpio -- whose aliases include ‘Bugsy,’ ‘Sinister,’ and ‘Sins’ -- is alleged to have killed his girlfriend, Lauren Olguin, in April, while on parole for a 2001 conviction for assault with a firearm and other violations. Olguin reportedly was 17 weeks pregnant.

“His pattern is one of violence, and he is always armed,” FBI Special Agent Scott Garriola said in a statement earlier this month, NBC News reported. "He is the definition of a continuing threat to the community."

The FBI says 508 people have been on the list, which was established in March 1950, and 475 fugitives have since been apprehended.

Additional information will be provided by the FBI and other law enforcement Tuesday morning. 

Fox News' Lee Ross and The Associated Press contributed to this report.