(CNN) -- Federal agents say they've now linked 11 killings to admitted serial killer Israel Keyes and are looking into possible ties to killings in other countries.
Keyes killed himself in December, about nine months after his arrest in the slaying of an Anchorage, Alaska, coffee barista. Police said he admitted to at least seven other slayings, from Vermont to Washington state, before his death.
In a statement issued Monday afternoon, the FBI office in Anchorage said agents have now added three more to that grim tally, based on his statements:
-- a pale-skinned woman in an older car, "possibly having a wealthy grandmother"
-- one in which the victim was posed to make it look like the death had been an accident
-- one "in Texas or a surrounding state" that he had denied committing before his death.
They also asked the public to share any information they had regarding Keyes' travels in Canada, Mexico and Belize between 2001 and 2008.
"Keyes traveled internationally and it is unknown if he committed any homicides while outside of the United States," the FBI statement said.
Keyes lived in upstate New York at one point and "reported several trips to Montreal in which he sought out prostitutes" and drove through western Canada on his way to Alaska, where he lived before his arrest.
The FBI on Tuesday released a detailed interactive map of Keyes' travels dating back to 1997 in hopes that the information might spur tips.
Pins on the map show Keyes' location on specific dates.
For instance, from March 1, 2005: "Day canoe trip to unspecified location; spotted camping at location only accessible by boat - Washington state," the interactive says. The pin points to a mountainous region east of Seattle.
In April and May of 2007, the pins put Keyes in specific locations in California, including "Hotel reservation (Best Western) - Kettleman City, California. April 27 - 28, 2007," and "Reservation (Safari West wildlife preserve) - Santa Rosa, California. May 3, 2007."
"If we have a missing person identified in a particular area, we work closely with that local police department to either connect the person to Keyes or not," Jolene Goeden, FBI special agent in Anchorage, said in a statement accompanying the interactive. "We have his DNA."
Videos of Keyes' interrogations are viewable on the FBI's website.
'A murder addict'
An Anchorage police officer described Keyes as a kind of murder addict who hunted victims in remote locations like parks, campgrounds or hiking trails.
An Army veteran and contractor, Keyes studied other serial killers but "was very careful to say he had not patterned himself after any other serial killer," Detective Monique Doll said in December.
Keyes killed himself by slitting one of his wrists and strangling himself with bedding, police said. He left behind an extensive, four-page note that expressed no remorse nor offer any clues to other slayings.
Investigators said he had "a meticulous and organized approach to his crimes," stashing weapons, cash and items used to dispose of bodies in several locations to prepare for future crimes.
Authorities have dug up two of those caches -- one in Eagle River, Alaska, outside Anchorage, and one near a reservoir in the Adirondack Mountains of New York.
Keyes also said he robbed banks to finance his travels, and investigators have corroborated his role in two holdups, the FBI said.
CNN's Brad Lendon contributed to this report.