In a post on the social networking site, Willie Davis Hines Jr. claimed the death of his pregnant girlfriend Tatjana Cruz was an accident.
Hines, 23, has been in hiding since he was last seen running from the couple's home in Adelanto, just west of Victorville, last week.
"It was an accident," read a portion of a long explanatory post on Hines Jr.'s Facebook wall.
Sherriff's deputies were called to the home in the 14500 block of Blue Sage Road after neighbors reportedly heard a loud and violent argument coming from inside.
"When she was transported to the hospital on Wednesday, she was suffering severe blunt force trauma," said Jodi Miller of the San Bernardino County Sheriff's Department. "When she was admitted into the hospital, that's when the fetus for the unborn child she was caring was pronounced deceased."
Investigators say the 5-month-old fetus likely died as a result of the brutal beating. According to a friend who posted on Facebook, the baby was a girl.
Cruz died two days later after she was removed from life support.
That same day, Hines posted an explanation stating there was more to the story than was being told.
"I fled the scene because i don't think there is any way to prove that this is not just a (sic) act of pure hate," the post said.
It's unclear if Hines is behind the post, which attempts to shift some of the blame for the couple's rocky relationship on Cruz's mental state.
Homicide investigators are aware of the posting and have been monitoring Hines' Facebook site closely.
"There has been some posting, some updates, on his Facebook page and law enforcement would definitely like to talk to him and find out exactly what did happen," Miller said.
Following Friday's post, family and friends of Hines left messages of support, some encouraging him to turn himself in.
According to other posts on Facebook, Cruz may have been a mother of two young boys, one of which may have witnessed her death.
Anyone with information on the whereabouts of Hines is asked to contact the San Bernardino County Sheriff's Department at (800) 783-7463.