Just weeks after her son was gunned down on Newfield Street in Buffalo and left for dead, Carmen Maldonado Grajales traveled to Puerto Rico in what prosecutors believe was a maternal mission in search of the killer.
A few days later, she was dead, too.
Officially, three years later, the two murders remain unsolved. But prosecutors say they know who killed Grajales' son, Dustin Ortiz Maldonado.
They also believe the same man, Christian O. Dalmau, was in Puerto Rico when Grajales disappeared.
"For all of these circumstances to be a pure coincidence would make the defendant incredibly unlucky," Assistant U.S Attorney Wei Xiang said in a recent court filing.
Now in custody, Dalmau was never charged with murder but he was arrested, and eventually pleaded guilty, to a gun possession charge involving the murder weapon used in the killing of Maldonado.
Prosecutors say Dalmau was arrested just minutes after Maldonado was shot and that, when Dalmau was found, he was still inside the GMC Yukon they believe was at the murder scene.
They also found the loaded 9-mm semi-automatic handgun used to kill Maldonado inside the SUV with Dalmau's DNA on the weapon.
"The victim had been arguing in Spanish with occupants of the Yukon," Xiang says in a sentencing memo about Dalmau. "The Yukon then drove away, leaving the victim lying on the ground with gunshot wounds to his head."
Xiang would not comment on the allegations against Dalmau. But in court papers, he outlined the evidence linking him to Maldonado's killing on that April day in 2014. He says the two were drug associates and that Maldonado owed money to Dalmau.
The government stops far short of accusing Dalmau of also killing Maldonado's mother, Grajales. Instead it refers to the circumstances that led to her disappearance and her belief that someone in Puerto Rico was responsible for her son's murder in Buffalo.
Xiang notes that when Grajales' "torso" was found, there were media accounts of the murder, some of them with her photo.
"She went to Puerto Rico and drew some obviously unwanted attention to someone or some group of individuals who she accused," Xiang says in his court papers. "Shortly thereafter, she disappeared."
So why wasn't Dalmau ever charged with murder?
Xiang acknowledges he doesn't have enough evidence to bring a federal murder charge against Dalmau, and specifically mentions the "reluctance of witnesses" to testify about what happened that day.
The Erie County District Attorney's Office, meanwhile, says Maldonado's murder remains under investigation.
Dalmau, who is scheduled to be sentenced on his gun conviction later this month, has a far different take on why he hasn't been charged with murder.
"The government wants this court to give the defendant the sentence of a man convicted of murder without having enough evidence to charge the man with murder," defense lawyer Gregory Val Bitterman said in his response.
Bitterman declined to comment on the allegations against his client but, in court papers, suggests they are based on a manufactured tale chock full of "factual inaccuracies."
He pointed to the lack of fingerprints and the presence of many people's DNA on the gun. He also noted the absence of any witnesses placing Dalmau at the murder scene.
"As part of his guilty plea, the defendant admitted that he knowingly possessed a gun," Bitterman said in his sentencing memo. "The government then attempts to confuse the court into believing that the defendant committed a murder."
Under federal sentencing guidelines, Dalmau is looking at a maximum of 10 years in prison for his gun possession conviction. Prosecutors are asking for the maximum. Dalmau, who has a wife and six kids in Puerto Rico, is asking for 10 to 16 months.
Throughout his response, Bitterman is dismissive of the government's allegations, saying they're baseless and unfounded. He also suggests at one point that the prosecution's attempts to link Dalmau to Gajales' disappearance topped the list of outrageous claims.
Bitterman says there are no flight records or any other evidence that his client was in Puerto Rico at that time and, if he was, he was there to see his wife and children.
"This is the peak of the government's attempt to create a mountain of evidence that does not exist," he says.
In his plea agreement, Dalmau admits possessing the handgun that killed Maldonado but stops short of admitting any involvement in the murder.
Beyond the gun, the government says its evidence includes the "multiple witnesses" who heard three to four gunshots before spotting Maldonado's body on Newfield Street. Prosecutors also claim the 17-round magazine in Dalmau's weapon contained only 13 rounds at the time of his arrest by Buffalo police a few minutes later.
Xiang also points to a GPS with Maldonado's Buffalo address entered into the device. He says it was found in the Yukon, next to Dalmau's seat.
Even more important, perhaps, was the relationship between Dalmau and Maldonado. Investigators claim the two were drug associates and that Maldonado owed money to Dalmau.
"When the victim could not pay, the defendant shot him," Xiang says in his court papers.
The government's sentencing memo also details Dalmau's alleged involvement with cocaine trafficking in Puerto Rico and his more recent association with known cocaine traffickers in Pennsylvania.
Despite all that, Dalmau has never been charged with drug dealing.
Bitterman says the government allegations are filled with "outright lies" and there's not a "shred of evidence" backing up the allegation of a drug association between his client and Maldonado.
He also challenges the "quantum leap" the government took in linking his client to Maldonado's murder. He points to the absence of a single witness to the alleged shooting, and wonders why investigators never suspected the individual who was with Dalmau that day.
"What the government does not state," he says, "is that there were at least two people in the car at the scene of the shooting, not just the defendant."
Dalmau is scheduled to be sentenced by U.S. District Judge Ricard J. Arcara on April 26.