FORT WORTH — An Arlington man pleaded guilty Monday to fatally stabbing his former girlfriend and was sentenced to 40 years in prison.Larry Fikes, 39, stabbed Angela Bynum, 32, the mother of his toddler son, at least nine times, the Tarrant County district attorney’s office said in a news release.Bynum was found dead Jan. 13, 2013, in her apartment in the 2300 block of North Texas 360 in Grand Prairie. According to an arrest warrant affidavit, when detectives entered the apartment, they found “a bloody knife handle with a broken blade,” and “a metallic object consistent with a broken knife blade could be seen inside the victim’s body” Officers learned that Bynum and Fikes had a son, then 13 months old, who lived with Bynum but who was not in the apartment.The child was found with Fikes. Detectives learned that Fikes had gone to Bynum’s apartment on the morning of Jan. 12 to drop off the child as scheduled.Detectives noticed that he had “cuts on his right thumb, index finger, and abrasions on his right hand knuckles,” the affidavit stated. They got a search warrant for Fikes’ DNA.Investigators determined that Fikes stabbed Bynum on Jan. 12. When he left, he took the child, drove home and invited friends over to watch a football game, the news release said.The child is being reared by his maternal grandmother.Fikes reached a plea agreement Monday. His trial had been scheduled to begin this week. Fikes must serve 20 years before he is eligible for parole, prosecutors said. This includes material from Star-Telegram archives.