The father of a Monrovia woman, whose jailed boyfriend is suspected of assaulting and abducting her, joined authorities Thursday in asking for the public's help in locating the 31-year-old single mom.

Sheriff's homicide investigators believe Amanda Kathleen Custer was taken against her will the morning of July 29 by her boyfriend, Robert Anthony Camou, from his Monrovia home in the 600 block of Vaquero Road. Witnesses said they saw Camou load her "lifeless" body into the trunk of a Toyota Prius, said sheriff's homicide Lt. Scott Hoglund.

Sheriff's detectives say blood was found in the Monrovia residence, and blood drops were found in the cargo hatch of the Prius, along with a digging tool.

Camou, 27, was taken into custody in downtown Los Angeles on July 30, following a nearly five-hour standoff with authorities, but there was no sign of Custer. He's being held without bail on previously filed charges including assault and domestic violence.

At a news conference at the Sheriff's Homicide Bureau this morning, Hoglund displayed a map of areas in the Mt. Baldy and Lytle Creek areas where the suspect was believed to have driven the gray 2017 Prius between the time of the alleged abduction and his capture.

"It is such a broad area that we desperately need the community's assistance in trying to pinpoint a location of where this Prius may have been," Hoglund said.

Detectives were able to piece together some of Camou's movements after the alleged abduction because he was wearing an electronic monitoring device in connection with the assault case.

Hoglund said Camou went to a Del Taco on Foothill Boulevard in Glendora about 8:30 a.m., and a few minutes later, he visited a Shell gas station on Foothill Boulevard, where he bought cigarettes.

Shortly before 9 a.m., Camou was seen in the Claremont area on Baseline Road and Padua Avenue, and then he went east to an Arco station on Sierra Avenue in Fontana about 9:30 a.m., where he was shown on security video.

About that time, Camou apparently removed the electronic monitoring device, and there is about a five-hour gap in his known whereabouts until he visited a Chase bank ATM on Foothill Boulevard in Azusa about 2:40 p.m., Hoglund said.

Rick Custer appealed for anyone with information to call authorities.

"This is basically a plea to anybody out there -- especially on Monday the 29th of July -- that was hunting, or fishing, or mountain biking, that might have seen anything out of the ordinary," Custer said. "It might not have seemed important at that time, but it does now."

Custer said he had been to the area in search of his daughter.

"I've gone up there a couple of times myself, up to Lytle Creek-- no results," he said. "Some other family members have been out there -- no results. We just want to bring Amanda home.''

Sheriff's investigators last week expanded their search to include the area of Lytle Creek because Camou is believed to have great knowledge of the area, which is in the San Gabriel Mountains about 16 miles northwest of San Bernardino. They said Camou's car was spotted -- shortly after the alleged kidnapping -- traveling north on Padua Road in Claremont toward Mount Baldy.

Sheriff's officials previously asked to hear from anyone who may have seen Camou in a downtown Los Angeles bar the night of July 29. Cellphone video from the bar shows Camou during an open-mic event, singing an expletive-laden rap about killing a woman.

"I killed my (expletive) and buried that (expletive) in the (expletive) dirt," he is heard rapping. He goes on to claim he is being sought by police, before someone takes the microphone from him.

It was just hours after the video was taken that Camou was found in the back seat of the parked Prius in downtown Los Angeles and was eventually taken into custody after being flushed out with tear gas.

Camou and Custer had a tumultuous two-year relationship that included "numerous domestic violence incidents," Hoglund said previously. The pair lived down the street from one another.

According to court records, Camou had been scheduled to appear in a Pasadena courtroom July 29 on the assault and domestic violence case, but he was already on the lam and did not show up for the hearing, leading to the issuance of an arrest warrant.

Camou made brief appearances in court July 31 and Aug. 1. When he returns to court in September, a date is expected to be set for a hearing to determine if there is enough evidence for him to stand trial in the earlier case.

A redacted copy of the criminal complaint in that case, provided by the District Attorney's Office, identifies the alleged victim only as Amanda C. Camou was out of custody in that case, subject to electronic monitoring, over the objection of prosecutors, who had asked that he be held on $150,000 bail.

Custer -- who has an 8-year-old son -- filed court papers in February seeking a restraining order against Camou, claiming he showed up uninvited at her home and broke a double-pane window with a hatchet. Custer obtained the restraining order on April 22.

Anyone who was in the area of Mount Baldy Road, Glendora Ridge Road or Glendora Mountain Road on July 29 between 9 a.m. and 3:30 p.m. who may have seen Camou or Custer -- or the Prius he was driving -- was urged to call the Sheriff's Homicide Bureau at 323-890-5500. Anonymous tips can be submitted to Crime Stoppers at 800-222-TIPS or lacrimestoppers.org.