One is a female wrestler who allegedly earned the trust of elderly women, then strangled them. The other is a former soldier accused of luring gay men from bars and killing them.
Mexico City police had two suspected serial killers in custody on Thursday, saying they have solved the capital's infamous "Little Old Lady Killer" case and have broken another string of murders.
Authorities said Juana Barraza, 48, was caught fleeing a house on Wednesday where an 82-year-old woman had been strangled with a stethoscope. Prosecutors said they have evidence implicating Barraza as the notorious "Mataviejitas," or "Little Old Lady Killer," suspected in the slayings of at least 10 elderly women in the past two years.
Another suspect, Raul Osiel Marroquin, 29, was arrested on Monday in the killings of four gay men in the capital, police said.
Both suspects confessed to killing at least some of the victims when they were paraded in front of the media, a tradition in Mexico where police and prosecutors have faced withering criticism for failing to investigate, let alone solve, most crimes.
At a news conference on Thursday, Marroquin coldly described killing four gay men. Although there had been some reports of an increase in attacks against gays, the announcement of Marroquin's arrest was the first confirmation of a serial killer targeting homosexuals.
Police did not give details about what led to his arrest.
"I snuffed out four homosexuals that in some way were affecting society," Marroquin said.
He told reporters he would kill again, if given the chance, but would "refine his methods."
Unlike Marroquin's case, which was little known until his arrest, news of the "Little Old Lady Killer" grabbed headlines, frightening residents for two years.
Police had suspected the killer was a man dressed as a woman and spent months detaining, questioning and fingerprinting transvestites. Female serial killers are rare in any country, making up only 8 percent of all serial assassins in the US.
Mexico City Attorney General Bernardo Batiz said on Thursday that they have enough evidence to pin at least 10 deaths on Barraza, a former professional wrestler.
Barraza told police and reporters she did kill Reyes, but not the others.
"Yes, I did it," she said, smiling at the TV cameras as she was being taken away by police.