Shortly following the announcement of Onfroy's death, the Broward County Sheriff's Office offered a $3,000 bounty for any information leading to the arrest of any suspects. Originally, many fans of Onfroy's, numerous internet users and local residents suspected local Florida rappers Soldier Kidd and Soldier Jojo to be the killers of Onfroy due to several suspicious Instagram posts made by the pair with specific details that corroborated with witness reports, but these accusations were later dropped when Dedrick Williams and Michael Boatwright were arrested.

On June 20, 2018, two days after the murder, the Broward County Sheriff's Office arrested 22-year-old Dedrick Devonshay Williams in connection with Onfroy's murder. Williams was driving in his silver 2004 Honda before a traffic stop occurred. Williams was detained in the car chase that followed. Williams was identified by clothing he wore on June 18, which included orange sandals and a white tank top. The police matched images from security footage to recent pictures from Williams' Instagram feed, which featured "the same or similar bright orange sandals". He was also identified by employees who said they saw him enter RIVA Motorsports to buy a neoprene mask. After Williams' arrest, two more active warrants were issued.

On June 27, 22-year-old Robert Allen was named as a person of interest in the case, and was later arrested on July 26.

On July 5, 22-year-old Michael Boatwright was arrested by the Broward County Sheriff's Office on drug-related charges, but on July 10, Boatwright was visited by detectives while in jail and was presented with his arrest warrant for premeditated first-degree murder. Boatwright had searched for "accessory to murder" and "XXXTentacion" on his phone's web browser after the murder. The former search term was later revealed by Allen to be because Boatwright was incorrectly reassuring Allen that he could only be charged with accessory to murder since Allen was not the triggerman. Boatwright was determined to be the one who fatally shot Onfroy. The three men were later indicted by a grand jury, alongside a fourth, for Onfroy's murder.

On August 7, 20-year-old Trayvon Newsome was arrested.

Dedrick Williams was charged with dangerous and depraved first-degree murder and probation violation, and was denied bail. On June 25, he pleaded not guilty. Williams had been arrested multiple times prior.

During Williams' interrogation, he reportedly went from denying he was involved in the killing to remorse, saying it had cost him "sleepless nights" and that he did not confess earlier due to fear of being labeled a "snitch".

On July 10, Michael Boatwright was arrested and charged with premeditated first-degree murder. According to the Broward County Sheriff's Office, Boatwright was initially arrested on unrelated drug charges on July 5 before he was formally charged with Onfroy's murder on July 10.

On July 25, a third suspect, Robert Allen, 22, was taken into custody and charged with premeditated first-degree murder after U.S. Marshals found him at his sister's house in rural Georgia. He was booked in Dodge County, Georgia and was held without bond on a warrant from the Broward County Sheriff's Office.

On August 7, the Broward County Sheriff's Office announced on Twitter that Trayvon Newsome, 20, was taken into custody shortly before 5:00 p.m. EST and had been booked on charges of premeditated first-degree murder and robbery with a deadly weapon.

Jahseh Onfroy's father, Dwayne Onfroy, had stated that he wanted the death penalty for the shooter and life imprisonment without the possibility of parole for the accomplices. Since the perpetrators were charged in Florida, if convicted of first-degree murder, they would have been eligible for capital punishment. However, the prosecution decided to seek life in prison without the possibility of parole over the death penalty.

On August 12, 2022, Robert Allen pleaded guilty to the lesser conviction of second-degree murder in exchange for testimony against the other three defendants.

In October 2022, Boatwright's attorneys began to claim that he is incompetent to stand trial and requested that psychological experts be appointed to determine Boatwright's legal competence. Boatwright was declared mentally competent to stand trial.

After Boatwright's attorneys requested a psychological evaluation for him before a trial, he was evaluated and ruled competent to stand trial. Trial judge Michael Usan ruled on January 17, 2023, that Onfroy's past criminal history and personal character were irrelevant to the crime and would not be permitted subjects at trial. The trial initiated on February 7, 2023. Robert Allen had previously taken a plea deal for second-degree murder for his testimony against Boatwright, Newsome, and Williams. Boatwright's attorney claimed in his opening that the fact that Boatwright searched "accessory to murder" proved he was innocent, but this was later disproven by Allen, who said that Boatwright searched it because he misinformed Allen that Allen could only be charged with accessory rather than actual murder. A DNA analyst testified that Boatwright's DNA on the mask used in the murder was rarer than one in 929 nonillion.

On March 20, 2023, the eighth day of jury deliberations, Boatwright and his two other co-defendants were found guilty on all counts. Boatwright made headlines for the fact that he blew a kiss to XXXTentacion's family after he was found guilty, with much of the public expressing disgust for Boatwright's conduct. On April 6, 2023, his two co-defendants were sentenced to a term of life in prison without the possibility of parole, while Boatwright received two consecutive terms of life-without-parole, plus another consecutive 30 years. The presiding judge Michael Usan expressed his condemnation of Boatwright at his sentencing, stating to him,

You turned a robbery into a murder. And on that day when you stood there and fired that weapon, you didn't just end one life. You effectively ended five lives, including your own ... You will spend the rest of your life in prison. From here you will go and be placed in a cell that has a stainless steel slab attached to the wall. That's your bed. And next to it is a stainless steel sink and a stainless steel toilet. That's the furniture that you have in that cell. You'll spend every hour, and every day, and every week, and every year of your life in that cell. And one day, they'll come and open up that cell in the morning and you'll have passed on. And only on that day will you have served your sentence.

On March 20, 2023, all three defendants were found guilty on all counts. On April 6, 2023, they were all sentenced to life in prison without the possibility of parole.

Michael Boatwright
Boatwright in a 2023 prison photograph
Born	(1995-09-12) September 12, 1995 (age 29) Fort Lauderdale, Florida, U.S.
Education	Park Ridge Alternative Center (dropped out)
Occupation	Landscaper (formerly)
Known for	Murder of XXXTentacion
Criminal status	Incarcerated at Martin Correctional Institution
Allegiance	ZMF
Motive	Unknown
Criminal penalty	Life imprisonment without the possibility of parole (×2; consecutive), plus another consecutive 30 years
Details
Weapon	Short-barreled rifle
Date apprehended	July 5, 2018

Michael Sherrell Boatwright was born on September 12, 1995, in Fort Lauderdale, Florida. Authorities determined that Boatwright was the one who shot XXXTentacion three times without provocation and left him to die in his car.

He attended multiple high schools such as J. P. Taravella High School in Coral Springs and Northeast High School in Oakland Park, before being transferred to Pine Ridge Alternative Center in Fort Lauderdale. He dropped out of Pine Ridge during tenth grade.

Boatwright was arrested multiple times prior to the murder of XXXTentacion, mainly on drug charges. In 2013, he was arrested in Broward County for assault or battery on specified officials or employees. The same year, he was arrested again for selling cocaine or heroin within 1,000 feet of a school zone. For these charges, he was put on community control.

In 2015, Boatwright was arrested again for possession of cannabis and PVP, which also counted as a violation of his community control. Boatwright had already been in jail for an arrest on unrelated charges related to cocaine possession with intent to distribute before he was charged with the murder of Jahseh Onfroy.

Boatwright is affiliated with the Florida ZMF gang.

On April 6, 2023, he was sentenced to two consecutive sentences of life in prison without the possibility of parole, plus another 30 years consecutive for other charges.

Trayvon Demarcus Newsome was born on May 5, 1998, in Fort Lauderdale, Florida. He was one of the two gunmen in the murder. Little is known about his personal life, but he was living with co-conspirator Robert Allen at the time of the murder.

On April 6, 2023, he was sentenced to life in prison without the possibility of parole.

Dedrick Devonshay Williams was born on March 23, 1996, in Fort Lauderdale, Florida. He was the main orchestrator and planner in the murder of XXXTentacion.

Williams had attended Stranahan High School before dropping out in the eleventh grade. At the time of the murder, he lived with his partner Tenell Carter, who Williams referred to as his "wife". He stated that he has four children.

He had a significant past criminal record, which included offenses such as grand theft auto, burglary, theft, and assault. He was on probation by the time the murder of XXXTentacion occurred. He is affiliated with the ZMF gang, and was known to gang members and his friends as "Chucky".

On April 6, 2023, he was sentenced to life in prison without the possibility of parole.

Robert Allen IV was born on March 27, 1996, in Fort Lauderdale, Florida. Prior to the murder, Allen was already a convicted fraudster, and had also been convicted for carrying a concealed firearm and drug possession. He testified against the other three perpetrators at their 2023 trial. He was affiliated with the ZMF gang, and has cooperated with authorities to solve another unrelated cold case murder related to ZMF. He was known to gang members as "Big Rob". Allen is the only one of the four perpetrators to have apologized for his role in the murder, with presiding Judge Usan stating that he believed Allen, unlike the other three perpetrators, was truly remorseful. He stated at his sentencing:

To say I’m sorry does not even begin the true inner remorse I want to make known. I know that these words that I will speak will never erase the pain and sorrow and loss of what the family will have from now on. There isn’t a day that goes by that I don’t think about what happened and beg for forgiveness from God. If I have to die in prison then so be it, I know the risk I was taking. Let justice be served and I’ll know that was the right thing to do ... Please forgive me.

— Robert Allen

On May 17, 2023, Allen was sentenced to 7 years in prison with credit for time served, plus a consecutive 20 years probation. He was released from prison on October 26, 2023.

Following the announcement of Onfroy's murder, a makeshift memorial was quickly created by fans and local residents, consisting of lyrics from the artist and words of remembrance written in chalk stretching up to a hundred yards. The owner of RIVA Motorsports, where XXXTentacion was killed, held a vigil on June 19, 2018, the day after his murder. Hundreds gathered during the vigil and Broward County Sheriffs were forced to close the street. Shortly after, a walk commenced between Onfroy's fans. Onfroy's house in Parkland, Florida, which was being built at the time, was also memorialized by fans.

Internet personality Adam22, the creator of the podcast No Jumper for which Onfroy had his first professional interview, held a memorial a day after Onfroy's death in front of his BMX retail store OnSomeShit on Melrose Avenue in Los Angeles to a crowd of 354 people. The crowd eventually grew to over 1,000 and police in riot gear eventually appeared with police en route to disperse the crowd. According to reports, rubber bullets were shot and tear gas was used to disperse the crowd.

An open casket service for Onfroy took place at BB&T Center in Sunrise, Florida, on June 27, where fans were allowed to pay their respects. His private funeral took place a day later, where rappers Lil Uzi Vert, Lil Yachty, Lil Pump, Denzel Curry, and singer Erykah Badu were among the attendees. He was laid to rest in a gray mausoleum at the Gardens of Boca Raton Memorial Park, in Boca Raton, Florida.

In July 2023, Boatwright's criminal interrogation was made available to the public.

On June 19, the day after Onfroy's death, Billboard reported that Taylor Swift's Spotify single-day streaming record for "Look What You Made Me Do" was broken by Onfroy's track "Sad!", with over 10.4 million streams compared to Swift's 10.1 million streams. This was followed by a 17-fold sales increase across all streaming and download platforms, including a 7000-fold sales increase in CDs on Amazon.com. Onfroy's album ? was expected to return to the top five the week of his death following his murder, ultimately reaching number three with 90,000 album-equivalent units sold, up from 19,000 the last week. In the week following his murder, Onfroy's highest-charting single, "Sad!", went from 52nd to 1st on the Billboard Hot 100, making him the first artist to top the Hot 100 posthumously in a lead role since The Notorious B.I.G., with "Mo Money Mo Problems", in 1997. On June 28, his management team posthumously released the music video for "Sad!" on YouTube, which has received over 170 million views whilst the audio has over 1.9 billion listens on Spotify.

On June 22, 2018, rapper Juice Wrld released two tracks, "Rich and Blind" and "Legends", as a tribute to Onfroy and other rappers. The cover art for both songs reveals an Instagram DM conversation between him and Onfroy.

Between June 18 and October 21, singer Billie Eilish and her brother Finneas wrote a song dedicated to Onfroy titled "6.18.18", which was performed by Billie Eilish during their "1-by-1" tour.