FORT COLLINS, Colo. (AP) — The boyfriend of slain cross-country traveler Gabby Petito admitted killing her in a notebook discovered near his body in a Florida swamp, the FBI announced Friday.
It was the first time authorities squarely pinned the blame for Petito's death on Brian Laundrie, though he was the prime suspect all along.
Investigators meanwhile announced that Laundrie, 23, had sent text messages to intentionally deceive people that Petito, 22, was still alive after he beat and strangled her in late August, according to a statement released by the FBI in Denver.
"All logical investigative steps have been concluded in this case," FBI Denver Division Special Agent in Charge Michael Schneider said in the statement. "The investigation did not identify any other individuals other than Brian Laundrie directly involved in the tragic death of Gabby Petito."
This Aug. 12, 2021, file photo from video provided by the Moab, Utah, Police Department shows Brian Laundrie talking to a police officer after police pulled over the van he was traveling in with his girlfriend, Gabrielle "Gabby" Petito, near the entrance to Arches National Park in Utah.
Petito's body was found Sept. 19 at a campground near Grand Teton National Park in northwestern Wyoming. A coroner determined she'd died about three weeks earlier of "blunt-force injuries to the head and neck, with manual strangulation."
Laundrie returned home to Florida in early September but went missing soon after. In October, his parents found an item belonging to him in a nature preserve near their house.
Further searching turned up Laundrie's remains, a revolver, backpack and the notebook. Medical examiners determined Laundrie died of a self-inflicted gunshot wound.
The FBI did not specify what, exactly, Laundrie had written in the notebook and in the texts he'd sent to mislead. The texts were sent between Laundrie's phone and Petito's phone, according to the statement.
"The timing and content of these messages are indicative of Mr. Laundrie attempting to deceive law enforcement by giving the impression that Ms. Petito was still alive," the statement said.
Grand Teton was the last place the couple visited during a cross-country van trip last summer that ended with Laundrie mysteriously returning home alone in the vehicle.
The couple documented their trip on Instagram. They crossed Colorado and on Aug. 12 were stopped by police in Moab, Utah, after the two got into a scuffle.
Police video showed Petito describing a fight that escalated. Police concluded Petito was the aggressor but officers decided to separate them for the night rather than file charges.
Attorneys for the Petito and Laundrie families did not immediately respond Friday to emails and text messages seeking comment about the FBI's conclusions.
A world ablaze: Top images captured by AP photographers in 2021
A couple kiss in front of a barricade set on fire by demonstrators during clashes with police following a protest condemning the imprisonment of rap singer Pablo Hasél in Barcelona, Spain, on Feb. 18, 2021. Hasél was convicted of insulting the Spanish monarchy and praising terrorist violence.
President-elect Joe Biden, left, and Vice President Mike Pence, right, watch as Lady Gaga steps off the stage after performing the national anthem during the 59th Presidential Inauguration at the U.S. Capitol in Washington on Jan. 20, 2021.
Firefighters battle the Sugar Fire, part of the Beckwourth Complex Fire, in Doyle, Calif., on July 9, 2021.
Yemeni fighters backed by the Saudi-led coalition ride on the back of an armored vehicle as they leave the front lines of Marib, Yemen, on June 19, 2021.
People cry out as the body of their relative is recovered from the rubble of a building damaged by an earthquake in Mamuju, West Sulawesi, Indonesia, on Jan. 15, 2021.
Demonstrators attack a barricade protecting Mexico City's National Palace during a march to commemorate International Women's Day and protest against gender violence on March 8, 2021.
Yohaness, from Eritrea, prays with other migrants as they arrive at the coast of Italy aboard the Spanish vessel Open Arms on Jan. 4, 2021, after being rescued in the Mediterranean sea.
A penguin swims in an enclosure housing gentoo and chinstrap penguins at Mexico City's Inbursa Aquarium on Jan. 13, 2021.
A voodoo pilgrim bathes in a waterfall believed to have purifying powers during an annual celebration in Saut d' Eau, Haiti, on July 16, 2021.
A farmer smokes a bidi, or hand-rolled cigarette, during a tractor rally to protest new farm laws in Ghaziabad, on the outskirts of New Delhi, India, on Jan. 7, 2021.
A migrant is comforted by a member of the Spanish Red Cross at the Spanish enclave of Ceuta near the border of Morocco and Spain on May 18, 2021.
Honduran migrants clash with Guatemalan soldiers in Vado Hondo, Guatemala, on Jan. 17, 2021.
Shredded trees and the shells of homes lie half buried in mud near the Taal volcano almost a year after it erupted in Batangas province, a popular tourist destination just south of Manila, Philippines, on Jan. 10, 2021.
Tin Tin Win, center, weeps over the body of her son, Tin Htut Hein, at his funeral in Yangon, Myanmar, on Feb. 24, 2021. Tin Htut Hein was shot four days earlier while acting as a volunteer guard for a neighborhood watch group that was set up over fears that authorities were using criminals released from prison to spread fear and commit violence.
A woman holds a cutout of President Donald Trump's face at a rally in Washington in support of Trump called the "Save America Rally" on Jan. 6, 2021.
A health worker prepares Pfizer's COVID-19 vaccine at the National Kidney and Transplant Institute in Quezon City, Philippines, on Nov. 17, 2021. (AP Photo/Aaron Favila)
Mahavir Singh, 90, stands for a photograph as he participates in a protest against new farm laws at the border of Delhi and Uttar Pradesh states in India, on Jan. 8, 2021. (AP Photo/Altaf Qadri)
Nepalese supporters of the splinter group in the governing Nepal Communist Party celebrate in Kathmandu on Feb. 23, 2021, after the Supreme Court ordered the reinstatement of Parliament, which had been dissolved by the prime minister. (AP Photo/Niranjan Shrestha)
Police with guns drawn face off against rioters trying to break into the House Chamber at the U.S. Capitol in Washington, on Jan. 6, 2021. (AP Photo/J. Scott Applewhite)
U.S. Customs and Border Protection mounted officers attempt to contain migrants, mostly from Haiti, as they cross the Rio Grande from Ciudad Acuña, Mexico, into Del Rio, Texas, on Sept. 19, 2021. (AP Photo/Felix Marquez)
A man carries a mannequin dressed as Superman ahead of a no confidence vote against Romanian Prime Minister Florin Citu's government in Romania's parliament in Bucharest, on Oct. 5, 2021. (AP Photo/Andreea Alexandru)
Holocaust survivor Rivka Papo, 87, gets makeup applied during a special beauty pageant honoring Holocaust survivors in Jerusalem, on Nov. 16, 2021. (AP Photo/Oded Balilty)
Israeli Arabs stand under a waterfall during the Muslim Eid al-Adha holiday at the Gan HaShlosha national park near the northern Israeli town of Beit Shean, on July 21, 2021. Eid al-Adha meaning "Feast of Sacrifice," marks the willingness of the Prophet Ibrahim (Abraham to Christians and Jews) to sacrifice his son. (AP Photo/Oded Balilty)
Simone Biles of the United States trains on vault for artistic gymnastics at Ariake Gymnastics Centre in Tokyo, Japan, on July 22, 2021, ahead of the 2020 Summer Olympics. (AP Photo/Ashley Landis)
Vendors wear hats for shade as they sell cooking coal at a market in Cap-Haitien, Haiti, on July 22, 2021. (AP Photo/Matias Delacroix)
A home is engulfed in flames as the Dixie fire rages south of Janesville in Northern California, on Aug. 16, 2021. (AP Photo/Ethan Swope)
Men place a coffin containing the remains of Francois Elmay into a tomb after recovering his body from the rubble of a home destroyed four days earlier by a 7.2 magnitude earthquake in Tobek, Haiti, on Aug. 18, 2021. (AP Photo/Joseph Odelyn)
A child weeps as he is unloaded from an inflatable raft after being smuggled into the United States across the Rio Grande in Roma, Texas, on March 28, 2021. (AP Photo/Dario Lopez-Mills)
Young cadets attend a ceremony on the first day of school at a cadet lyceum in Kyiv, Ukraine, on Sept. 1, 2021. Ukraine marks Sept. 1 as Knowledge Day, the traditional launch of the academic year. (AP Photo/Efrem Lukatsky)
Guan Chenchen, of China, performs on the balance beam on her way to winning the gold medal during the artistic gymnastics women's apparatus final at the 2020 Summer Olympics, in Tokyo, Japan, on Aug. 3, 2021. (AP Photo/Ashley Landis)
Luciana Benetti, 16, embraces her pet pig Chanchi at home in Buenos Aires, Argentina, on Sept. 4, 2021. Benetti found her plans for a big traditional 15th birthday party scrapped due to the COVID-19 pandemic last year. In its place, her parents gave her a pig, which turned out to be a loyal and loving companion. (AP Photo/Natacha Pisarenko)
A model waits to have her headdress removed after a presentation of the William Zhang collection by designer Hongwei Zhang during the China Fashion Week in Beijing, on Sept. 8, 2021. (AP Photo/Ng Han Guan)
A firefighter places his hand on engraved names on the south memorial pool during a ceremony to commemorate the 20th anniversary of the Sept. 11 terrorist attacks on Sept. 11, 2021, at the National September 11 Memorial & Museum in New York. (AP Photo/John Minchillo)
Children watch a movie of the "Cinema no Morro" or "Cinema on the hill" project in a cultural center at Vila Cruzeiro favela in Rio de Janeiro, Brazil, on Sept. 13, 2021. (AP Photo/Silvia Izquierdo)
An Ultra-Orthodox Jewish man from the Kiryat Sanz Hassidic sect prays on a hill overlooking the Mediterranean Sea during a Tashlich ceremony in Netanya, Israel, on Sept. 14, 2021. Tashlich, which means "to cast away" in Hebrew, is the practice in which Jews symbolically "throw away" their sins by throwing a piece of bread, or similar food, into a large body of water before the Jewish holiday of Yom Kippur. (AP Photo/Ariel Schalit)
Children jump over a puddle of water as they play during a rainstorm on a street in Barcelona, Spain, on Sept. 18, 2021. (AP Photo/Emilio Morenatti)
Russian communist supporters hold flags and portraits of Vladimir Lenin as they walk to the mausoleum housing the Soviet founder's remains to mark the 151st anniversary of his birth on April 22, 2021, in Moscow. (AP Photo/Pavel Golovkin)
A man runs to escape the heat from multiple funeral pyres of COVID-19 victims at a crematorium on the outskirts of New Delhi, India, on April 29, 2021. (AP Photo/Amit Sharma)
A woman carries a wooden cross during a pilgrimage to pray that the Pacaya volcano decreases its activity, in San Vicente Pacaya, Guatemala, on May 5, 2021. The volcano, just 50 kilometers (31 miles) south of Guatemala's capital, became more active in early February. (AP Photo/Moises Castillo)
Father Felix Mendoza, a Venezuelan Catholic priest, prays over a woman who is crying out in physical pain, at a public hospital in Caracas, Venezuela, on May 11, 2021. (AP Photo/Ariana Cubillos)
A blast from an Israeli airstrike on a building in Gaza City throws dust and debris on May 13, 2021, as Hamas and Israel traded more rockets and airstrikes and Jewish-Arab violence raged across Israel at the end of the Muslim holy month of Ramadan. (AP Photo/Hatem Moussa)
A group of migrants arrive outside a holding center for migrants in the Spanish North African enclave of Melilla, on May 18, 2021, after crossing into Melilla in the early hours by jumping over the enclave's double fence. (AP Photo/Javier Bernardo)
Impoverished Sri Lankans salvage debris that washed ashore on May 26, 2021, from the burning Singaporean ship X-Press Pearl, which caught fire several days earlier off the coast of Colombo, Sri Lanka. (AP Photo/Eranga Jayawardena)
Anti-government protesters angry over proposed tax increases on public services, fuel, wages and pensions clash with police in Madrid, Colombia, on the outskirts of Bogota, on May 28, 2021. (AP Photo/Ivan Valencia)
New York Mets first baseman Pete Alonso walks to his position between innings of the team's baseball game against the Chicago Cubs on June 17, 2021, in New York. (AP Photo/Kathy Willens)
Health care worker Nazir Ahmed carries a cooler with vaccines and looks out from a hillock for Kashmiri shepherds to vaccinate in Tosamaidan, southwest of Srinagar, Indian controlled Kashmir, on June 21, 2021. (AP Photo/Dar Yasin)
Surgeon-turned-refugee Dr. Tewodros Tefera performs surgery on a man's severely infected toe, at the Sudanese Red Crescent clinic in Hamdayet, eastern Sudan, near the border with Ethiopia, on March 22, 2021. (AP Photo/Nariman El-Mofty)
Performers dressed as rescue workers gather around the Communist Party flag during a gala show ahead of the 100th anniversary of the founding of the Chinese Communist Party in Beijing, on June 28, 2021. (AP Photo/Ng Han Guan)
Kian Navales poses at home in Quezon city, Philippines, on July 6, 2021, holding a pillow with a photo on it of his late father, Arthur, who died from COVID-19. Navales, who also had the virus, says he misses going out for noodles with his dad. (AP Photo/Aaron Favila)
President Joe Biden speaks to reporters on the South Lawn of the White House in Washington after returning from a trip to Cincinnati, on July 21, 2021. (AP Photo/Susan Walsh)
A boy bicycle-kicks a ball in a flooded area of the Belen community in Iquitos, Peru, on March 20, 2021. (AP Photo/Rodrigo Abd)
A fighter loyal to the Tigray People's Liberation Front (TPLF) mans a guard post on the outskirts of the town of Hawzen, then-controlled by the group but later re-taken by government forces, in the Tigray region of northern Ethiopia on May 7, 2021. (AP Photo/Ben Curtis)
A Palestinian man carries an olive tree as he crosses illegally into Israel from the West Bank, through a gap in the separation barrier, south of the West Bank town of Hebron, on March 8, 2021. (AP Photo/Oded Balilty)
Victor Tripiana, 86, reaches out to touch the hand of his daughter-in-law, Silvia Fernandez Sotto, separated by a plastic sheet to prevent the spread of COVID-19, at the Reminiscencias residence for the elderly in Tandil, Argentina, on April 4, 2021. (AP Photo/Natacha Pisarenko)
Villas on the fronds of the Jumeirah Palm Island in Dubai, United Arab Emirates, are seen from the observation deck of The View at The Palm Jumeirah on April 6, 2021. (AP Photo/Kamran Jebreili)
In this photo created with an in-camera multiple exposure, registered nurse Lisa Lampkin, part of the first group of nurses who had been treating coronavirus patients in an intensive care unit, stands for a photo in the empty COVID-19 ICU at Providence Mission Hospital in Mission Viejo, Calif., on April 6, 2021. "I would go home, try to sleep," she says. Then she would "wake up to the reality of this pandemic again." (AP Photo/Jae C. Hong)
A funeral worker removes empty coffins that held remains that were later cremated at La Recoleta cemetery in Santiago, Chile, during the coronavirus pandemic, on April 21, 2021. (AP Photo/Esteban Felix)
Military police officer Everaldo Pinto, dressed as superhero Captain America, greets children and encourages them to protect themselves during the COVID-19 pandemic in Petropolis, Rio de Janeiro state, Brazil, on April 15, 2021. (AP Photo/Silvia Izquierdo)
A train passes a railroad crossing surrounded by floodwaters from rain and melting snow in Nidderau near Frankfurt, Germany, on Feb. 3, 2021. (AP Photo/Michael Probst)
Trump supporters try to break through a police barrier at the Capitol in Washington, on Jan. 6, 2021, as Congress prepared to affirm President-elect Joe Biden's victory. (AP Photo/John Minchillo)
Migrants and refugees of various African nationalities wait for assistance aboard an overcrowded wooden boat in the Mediterranean Sea 122 miles off the coast of Libya as aid workers on the Spanish search and rescue vessel Open Arms approach on Feb. 12, 2021. (AP Photo/Bruno Thevenin)
A ray of sunshine illuminates the face of a baby Jesus figure, held by a man waiting to have the figurine blessed, at the Purification of Our Lady of Candlemas Chapel in Mexico City, on Feb. 2, 2021. (AP Photo/Rebecca Blackwell)
Khushi Mir, left, a transgender Kashmiri, relaxes with friends after a meeting of community members in the outskirts of Srinagar, Indian controlled Kashmir, on June 4, 2021. Khushi and four young boys have begun a volunteer group to distribute food kits to the transgender community. (AP Photo/Dar Yasin)
An Ethiopian woman argues with others over the allocation of yellow split peas distributed by the Relief Society of Tigray in the town of Agula, in the Tigray region of northern Ethiopia, on May 8, 2021. In war-torn Tigray, it is not just that people are starving; it is that many are being starved, The Associated Press found. (AP Photo/Ben Curtis)
Relatives and neighbors wail during the funeral of Waseem Ahmed, a policeman who was killed in a shootout, on the outskirts of Srinagar, Indian controlled Kashmir, on June 13, 2021. (AP Photo/Dar Yasin)
A wood frog looks out from the clover in East Waterford, Pa., on June 6, 2021. (AP Photo/Carolyn Kaster)
Switzerland's Marc Hirschi lies on the side of the road after crashing during the first stage of the Tour de France cycling race on June 26, 2021. (AP Photo/Daniel Cole)
Ultra-Orthodox Jewish men and children read by candle light from the book of Eicha (Book of Lamentations) during the annual Tisha B'Av (Ninth of Av) fasting and memorial day, commemorating the destruction of ancient Jerusalem temples, in the Ultra-Orthodox neighborhood of Mea Shearim in Jerusalem, on July 17, 2021. (AP Photo/Oded Balilty)
Supporters of President Donald Trump climb the west wall of the the U.S. Capitol in Washington as they try to storm the building on Jan. 6, 2021, while inside Congress prepared to affirm President-elect Joe Biden's election victory. (AP Photo/Jose Luis Magana)
A man watches as a wildfire approaches Kochyli beach near the village of Limni, Greece, about 160 kilometers (100 miles) north of Athens, on Aug. 6, 2021. (AP Photo/Thodoris Nikolaou)
Stephen Mudoga, 12, tries to chase away a swarm of locusts on his farm as he returns home from school, at Elburgon, in Nakuru county, Kenya, on March 17, 2021. (AP Photo/Brian Inganga)
Larrecsa Cox peers around a stairwell in an abandoned home frequented by people struggling with drug addiction in Huntington, W.Va., on March 18, 2021. Cox leads the Quick Response Team, whose mission is to save every person who survives an overdose from the next one. (AP Photo/David Goldman)
Migrants walk on a dirt road along the Rio Grande in Mission, Texas, on March 23, 2021, after crossing the U.S.-Mexico border. (AP Photo/Julio Cortez)
Jen Ho Lee, a 76-year-old South Korean immigrant, poses in her apartment in Los Angeles on March 31, 2021, with a sign from a recent rally she attended in Koreatown against anti-Asian hate crimes. (AP Photo/Jae C. Hong)
A patient in a car receives oxygen provided by a gurdwara, a Sikh place of worship, in New Delhi, India, on April 24, 2021. India's health system has been overwhelmed by the coronavirus pandemic, leaving patients desperate for oxygen and other supplies. (AP Photo/Altaf Qadri)
Displaced Tigrayan women, one wearing an Ethiopian Orthodox Christian cross, sit in a metal shack to eat food donated by local residents at a reception center for the internally displaced in Mekele, in the Tigray region of northern Ethiopia, on May 9, 2021. (AP Photo/Ben Curtis)
A ballerina in the National Opera performs during the avant premiere staging of the 1870 comic ballet Coppelia in Bucharest, Romania, on May 12, 2021. (AP Photo/Andreea Alexandru)
River herring, also known as alewives, swim in a stream on May 16, 2021, in Franklin, Maine. The fish were once headed for the endangered species list but have been making a comeback in some U.S. states. (AP Photo/Robert F. Bukaty)
A group of migrants mainly from Honduras and Nicaragua wait along a road after turning themselves in upon crossing the U.S.-Mexico border, in La Joya, Texas, on May 17, 2021. (AP Photo/Gregory Bull)
Lucy Mbewe, a traditional birth attendant, assists a pregnant woman at her home in Simika Village, Chiradzulu, southern Malawi, on May 23, 2021. (AP Photo/Thoko Chikondi)
Daniel Turjman, 60, rests in a bomb shelter that is also used as a synagogue near his apartment building in Ashdod, Israel, on May 19, 2021, as fighting escalates between the Israeli military Hamas militants. (AP Photo/Heidi Levine)
Taliban fighters ride in a boat in the Qargha dam outside Kabul, Afghanistan, on Sept. 24, 2021. (AP Photo/Bernat Armangue)
Laila poses for a photo on Sept. 27, 2021, as she plays in a poor neighborhood in Kabul, Afghanistan, where hundreds of internally displaced people from the eastern part of the country have been living for years. (AP Photo/Felipe Dana)
Police beat a woman participating in a protest over the death in prison of Mushtaq Ahmed, a writer who was arrested on charges of violating a sweeping digital security law, in Dhaka, Bangladesh, on Feb. 26, 2021. Ahmed, 53, was arrested in May 2020 for making comments on social media that criticized how the government of Prime Minister Sheikh Hasina was handling the coronavirus pandemic. (AP Photo/Mahmud Hossain Opu)
Medical students grieve and some flash the three-fingered salute during the funeral of their fellow student Khant Ngar Hein in Yangon, Myanmar, on March 16, 2021. Khant Ngar Hein, 18, was shot in the chest two days earlier by security forces during a protest against the military takeover of the country. (AP Photo)